diff --git a/CMakeLists.txt b/CMakeLists.txt
index b60106d..086a090 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -83,6 +83,11 @@ set(Aquila_HEADERS
     aquila/source/window/HammingWindow.h
     aquila/source/window/HannWindow.h
     aquila/source/window/RectangularWindow.h
+    aquila/source/window/WelchWindow.h
+    aquila/source/window/CosineWindow.h
+    aquila/source/window/NuttallWindow.h
+    aquila/source/window/BlackmanNuttallWindow.h
+    aquila/source/window/BlackmanHarrisWindow.h
     aquila/transform/Fft.h
     aquila/transform/Dft.h
     aquila/transform/AquilaFft.h
@@ -117,6 +122,11 @@ set(Aquila_SOURCES
     aquila/source/window/GaussianWindow.cpp
     aquila/source/window/HammingWindow.cpp
     aquila/source/window/HannWindow.cpp
+    aquila/source/window/WelchWindow.cpp
+    aquila/source/window/CosineWindow.cpp
+    aquila/source/window/NuttallWindow.cpp
+    aquila/source/window/BlackmanNuttallWindow.cpp
+    aquila/source/window/BlackmanHarrisWindow.cpp
     aquila/transform/Dft.cpp
     aquila/transform/AquilaFft.cpp
     aquila/transform/OouraFft.cpp
diff --git a/aquila/source.h b/aquila/source.h
index fe39dc8..f648095 100644
--- a/aquila/source.h
+++ b/aquila/source.h
@@ -39,5 +39,10 @@
 #include "source/window/HammingWindow.h"
 #include "source/window/HannWindow.h"
 #include "source/window/RectangularWindow.h"
+#include "source/window/WelchWindow.h"
+#include "source/window/BlackmanHarrisWindow.h"
+#include "source/window/NuttallWindow.h"
+#include "source/window/BlackmanNuttallWindow.h"
+#include "source/window/CosineWindow.h"
 
 #endif // AQUILA_SOURCE_H
diff --git a/aquila/source/window/BlackmanHarrisWindow.cpp b/aquila/source/window/BlackmanHarrisWindow.cpp
new file mode 100644
index 0000000..7c39fd4
--- /dev/null
+++ b/aquila/source/window/BlackmanHarrisWindow.cpp
@@ -0,0 +1,41 @@
+/**
+ * @file BlackmanHarrisWindow.cpp
+ *
+ * Blackman-Harris window.
+ *
+ * This file is part of the Aquila DSP library.
+ * Aquila is free software, licensed under the MIT/X11 License. A copy of
+ * the license is provided with the library in the LICENSE file.
+ *
+ * @package Aquila
+ * @version 3.0.0-dev
+ * @author Zbigniew Siciarz
+ * @date 2007-2014
+ * @license http://www.opensource.org/licenses/mit-license.php MIT
+ * @since 3.0.0
+ */
+
+#include "BlackmanHarrisWindow.h"
+#include <cmath>
+
+namespace Aquila
+{
+    /**
+     * Creates Blackman-Harris window of given size.
+     *
+     * @param size window length
+     */
+    BlackmanHarrisWindow::BlackmanHarrisWindow(std::size_t size):
+        SignalSource()
+    {
+        m_data.reserve(size);
+        for (std::size_t n = 0; n < size; ++n)
+        {
+            m_data.push_back(
+                0.35875 - 0.48829 * std::cos(2.0 * M_PI * n / double(size - 1)) +
+                    0.14128 * std::cos(4.0 * M_PI * n / double(size - 1)) -
+                    0.01168 * std::cos(6.0 * M_PI * n / double(size - 1))
+            );
+        }
+    }
+}
diff --git a/aquila/source/window/BlackmanHarrisWindow.h b/aquila/source/window/BlackmanHarrisWindow.h
new file mode 100644
index 0000000..7a3ce5c
--- /dev/null
+++ b/aquila/source/window/BlackmanHarrisWindow.h
@@ -0,0 +1,37 @@
+/**
+ * @file BlackmanHarrisWindow.h
+ *
+ * Blackman-Harris window.
+ *
+ * This file is part of the Aquila DSP library.
+ * Aquila is free software, licensed under the MIT/X11 License. A copy of
+ * the license is provided with the library in the LICENSE file.
+ *
+ * @package Aquila
+ * @version 3.0.0-dev
+ * @author Zbigniew Siciarz
+ * @date 2007-2014
+ * @license http://www.opensource.org/licenses/mit-license.php MIT
+ * @since 3.0.0
+ */
+
+#ifndef BLACKMANHARRISWINDOW_H
+#define BLACKMANHARRISWINDOW_H
+
+#include "../../global.h"
+#include "../SignalSource.h"
+#include <cstddef>
+
+namespace Aquila
+{
+    /**
+     * Nuttall window.
+     */
+    class AQUILA_EXPORT BlackmanHarrisWindow : public SignalSource
+    {
+    public:
+        BlackmanHarrisWindow(std::size_t size);
+    };
+}
+
+#endif // BLACKMANHARRISWINDOW_H
diff --git a/aquila/source/window/BlackmanNuttallWindow.cpp b/aquila/source/window/BlackmanNuttallWindow.cpp
new file mode 100644
index 0000000..4fd5db9
--- /dev/null
+++ b/aquila/source/window/BlackmanNuttallWindow.cpp
@@ -0,0 +1,41 @@
+/**
+ * @file BlackmanNuttallWindow.cpp
+ *
+ * Blackman-Nuttall window.
+ *
+ * This file is part of the Aquila DSP library.
+ * Aquila is free software, licensed under the MIT/X11 License. A copy of
+ * the license is provided with the library in the LICENSE file.
+ *
+ * @package Aquila
+ * @version 3.0.0-dev
+ * @author Zbigniew Siciarz
+ * @date 2007-2014
+ * @license http://www.opensource.org/licenses/mit-license.php MIT
+ * @since 3.0.0
+ */
+
+#include "BlackmanNuttallWindow.h"
+#include <cmath>
+
+namespace Aquila
+{
+    /**
+     * Creates Blackman-Nuttall window of given size.
+     *
+     * @param size window length
+     */
+    BlackmanNuttallWindow::BlackmanNuttallWindow(std::size_t size):
+        SignalSource()
+    {
+        m_data.reserve(size);
+        for (std::size_t n = 0; n < size; ++n)
+        {
+            m_data.push_back(
+                0.3635819 - 0.4891775 * std::cos(2.0 * M_PI * n / double(size - 1)) +
+                    0.1365995 * std::cos(4.0 * M_PI * n / double(size - 1)) -
+                    0.0106411 * std::cos(6.0 * M_PI * n / double(size - 1))
+            );
+        }
+    }
+}
diff --git a/aquila/source/window/BlackmanNuttallWindow.h b/aquila/source/window/BlackmanNuttallWindow.h
new file mode 100644
index 0000000..5139258
--- /dev/null
+++ b/aquila/source/window/BlackmanNuttallWindow.h
@@ -0,0 +1,37 @@
+/**
+ * @file BlackmanNuttallWindow.h
+ *
+ * Blackman-Nuttall window.
+ *
+ * This file is part of the Aquila DSP library.
+ * Aquila is free software, licensed under the MIT/X11 License. A copy of
+ * the license is provided with the library in the LICENSE file.
+ *
+ * @package Aquila
+ * @version 3.0.0-dev
+ * @author Zbigniew Siciarz
+ * @date 2007-2014
+ * @license http://www.opensource.org/licenses/mit-license.php MIT
+ * @since 3.0.0
+ */
+
+#ifndef BLACKMANNUTTALLWINDOW_H
+#define BLACKMANNUTTALLWINDOW_H
+
+#include "../../global.h"
+#include "../SignalSource.h"
+#include <cstddef>
+
+namespace Aquila
+{
+    /**
+     * Nuttall window.
+     */
+    class AQUILA_EXPORT BlackmanNuttallWindow : public SignalSource
+    {
+    public:
+        BlackmanNuttallWindow(std::size_t size);
+    };
+}
+
+#endif // BLACKMANNUTTALLWINDOW_H
diff --git a/aquila/source/window/CosineWindow.cpp b/aquila/source/window/CosineWindow.cpp
new file mode 100644
index 0000000..de2ddf5
--- /dev/null
+++ b/aquila/source/window/CosineWindow.cpp
@@ -0,0 +1,38 @@
+/**
+ * @file CosineWindow.cpp
+ *
+ * Cosine window.
+ *
+ * This file is part of the Aquila DSP library.
+ * Aquila is free software, licensed under the MIT/X11 License. A copy of
+ * the license is provided with the library in the LICENSE file.
+ *
+ * @package Aquila
+ * @version 3.0.0-dev
+ * @author Zbigniew Siciarz
+ * @date 2007-2014
+ * @license http://www.opensource.org/licenses/mit-license.php MIT
+ * @since 3.0.0
+ */
+
+#include "CosineWindow.h"
+#include <cmath>
+
+namespace Aquila
+{
+    /**
+     * Creates Cosine window of given size.
+     *
+     * @param size window length
+     */
+    CosineWindow::CosineWindow(std::size_t size):
+        SignalSource()
+    {
+
+        const double lhalf = ((double)size - 1.0) / 2.0; // L / 2
+        m_data.reserve(size);
+        for (std::size_t n = 0; n < size; ++n) {
+            m_data.push_back(std::sin(n * M_PI / double(size - 1)));
+        }
+    }
+}
diff --git a/aquila/source/window/CosineWindow.h b/aquila/source/window/CosineWindow.h
new file mode 100644
index 0000000..8acd82f
--- /dev/null
+++ b/aquila/source/window/CosineWindow.h
@@ -0,0 +1,37 @@
+/**
+ * @file CosineWindow.h
+ *
+ * Cosine window.
+ *
+ * This file is part of the Aquila DSP library.
+ * Aquila is free software, licensed under the MIT/X11 License. A copy of
+ * the license is provided with the library in the LICENSE file.
+ *
+ * @package Aquila
+ * @version 3.0.0-dev
+ * @author Zbigniew Siciarz
+ * @date 2007-2014
+ * @license http://www.opensource.org/licenses/mit-license.php MIT
+ * @since 3.0.0
+ */
+
+#ifndef COSINEWINDOW_H
+#define COSINEWINDOW_H
+
+#include "../../global.h"
+#include "../SignalSource.h"
+#include <cstddef>
+
+namespace Aquila
+{
+    /**
+     * Cosine window.
+     */
+    class AQUILA_EXPORT CosineWindow : public SignalSource
+    {
+    public:
+        CosineWindow(std::size_t size);
+    };
+}
+
+#endif // COSINEWINDOW_H
diff --git a/aquila/source/window/NuttallWindow.cpp b/aquila/source/window/NuttallWindow.cpp
new file mode 100644
index 0000000..3bad40e
--- /dev/null
+++ b/aquila/source/window/NuttallWindow.cpp
@@ -0,0 +1,41 @@
+/**
+ * @file NuttallWindow.cpp
+ *
+ * Nuttall window.
+ *
+ * This file is part of the Aquila DSP library.
+ * Aquila is free software, licensed under the MIT/X11 License. A copy of
+ * the license is provided with the library in the LICENSE file.
+ *
+ * @package Aquila
+ * @version 3.0.0-dev
+ * @author Zbigniew Siciarz
+ * @date 2007-2014
+ * @license http://www.opensource.org/licenses/mit-license.php MIT
+ * @since 3.0.0
+ */
+
+#include "NuttallWindow.h"
+#include <cmath>
+
+namespace Aquila
+{
+    /**
+     * Creates Nuttall window of given size.
+     *
+     * @param size window length
+     */
+    NuttallWindow::NuttallWindow(std::size_t size):
+        SignalSource()
+    {
+        m_data.reserve(size);
+        for (std::size_t n = 0; n < size; ++n)
+        {
+            m_data.push_back(
+                0.355768 - 0.487396 * std::cos(2.0 * M_PI * n / double(size - 1)) +
+                    0.144232 * std::cos(4.0 * M_PI * n / double(size - 1)) -
+                    0.012604 * std::cos(6.0 * M_PI * n / double(size - 1))
+            );
+        }
+    }
+}
diff --git a/aquila/source/window/NuttallWindow.h b/aquila/source/window/NuttallWindow.h
new file mode 100644
index 0000000..f5c2de3
--- /dev/null
+++ b/aquila/source/window/NuttallWindow.h
@@ -0,0 +1,37 @@
+/**
+ * @file NuttallWindow.h
+ *
+ * Nuttall window.
+ *
+ * This file is part of the Aquila DSP library.
+ * Aquila is free software, licensed under the MIT/X11 License. A copy of
+ * the license is provided with the library in the LICENSE file.
+ *
+ * @package Aquila
+ * @version 3.0.0-dev
+ * @author Zbigniew Siciarz
+ * @date 2007-2014
+ * @license http://www.opensource.org/licenses/mit-license.php MIT
+ * @since 3.0.0
+ */
+
+#ifndef NUTTALWINDOW_H
+#define NUTTALWINDOW_H
+
+#include "../../global.h"
+#include "../SignalSource.h"
+#include <cstddef>
+
+namespace Aquila
+{
+    /**
+     * Nuttall window.
+     */
+    class AQUILA_EXPORT NuttallWindow : public SignalSource
+    {
+    public:
+        NuttallWindow(std::size_t size);
+    };
+}
+
+#endif // NUTTALWINDOW_H
diff --git a/aquila/source/window/WelchWindow.cpp b/aquila/source/window/WelchWindow.cpp
new file mode 100644
index 0000000..127bc37
--- /dev/null
+++ b/aquila/source/window/WelchWindow.cpp
@@ -0,0 +1,40 @@
+/**
+ * @file WelchWindow.cpp
+ *
+ * Welch window.
+ *
+ * This file is part of the Aquila DSP library.
+ * Aquila is free software, licensed under the MIT/X11 License. A copy of
+ * the license is provided with the library in the LICENSE file.
+ *
+ * @package Aquila
+ * @version 3.0.0-dev
+ * @author Zbigniew Siciarz
+ * @date 2007-2014
+ * @license http://www.opensource.org/licenses/mit-license.php MIT
+ * @since 3.0.0
+ */
+
+#include "WelchWindow.h"
+#include <cmath>
+
+namespace Aquila
+{
+    /**
+     * Creates Welch window of given size.
+     *
+     * @param size window length
+     */
+    WelchWindow::WelchWindow(std::size_t size):
+        SignalSource()
+    {
+
+        const double lhalf = ((double)size - 1.0) / 2.0; // L / 2
+        m_data.reserve(size);
+        for (std::size_t n = 0; n < size; ++n)
+        {
+            double v = ((double)n - lhalf) / lhalf;
+            m_data.push_back(1 - (v * v));
+        }
+    }
+}
diff --git a/aquila/source/window/WelchWindow.h b/aquila/source/window/WelchWindow.h
new file mode 100644
index 0000000..bf8eeda
--- /dev/null
+++ b/aquila/source/window/WelchWindow.h
@@ -0,0 +1,37 @@
+/**
+ * @file WelchWindow.h
+ *
+ * Welch window.
+ *
+ * This file is part of the Aquila DSP library.
+ * Aquila is free software, licensed under the MIT/X11 License. A copy of
+ * the license is provided with the library in the LICENSE file.
+ *
+ * @package Aquila
+ * @version 3.0.0-dev
+ * @author Zbigniew Siciarz
+ * @date 2007-2014
+ * @license http://www.opensource.org/licenses/mit-license.php MIT
+ * @since 3.0.0
+ */
+
+#ifndef WELCHWINDOW_H
+#define WELCHWINDOW_H
+
+#include "../../global.h"
+#include "../SignalSource.h"
+#include <cstddef>
+
+namespace Aquila
+{
+    /**
+     * Welch window.
+     */
+    class AQUILA_EXPORT WelchWindow : public SignalSource
+    {
+    public:
+        WelchWindow(std::size_t size);
+    };
+}
+
+#endif // WELCHWINDOW_H
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 2b8571a..caa7bf4 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -39,6 +39,11 @@ set(Aquila_Test_SOURCES
     source/window/HammingWindow.cpp
     source/window/HannWindow.cpp
     source/window/RectangularWindow.cpp
+    source/window/BlackmanHarrisWindow.cpp
+    source/window/BlackmanNuttallWindow.cpp
+    source/window/NuttallWindow.cpp
+    source/window/WelchWindow.cpp
+    source/window/CosineWindow.cpp
     tools/TextPlot.cpp
     transform/AquilaFft.cpp
     transform/Dft.cpp
diff --git a/tests/source/window/BlackmanHarrisWindow.cpp b/tests/source/window/BlackmanHarrisWindow.cpp
new file mode 100644
index 0000000..abac7c1
--- /dev/null
+++ b/tests/source/window/BlackmanHarrisWindow.cpp
@@ -0,0 +1,31 @@
+#include "aquila/global.h"
+#include "aquila/source/window/BlackmanHarrisWindow.h"
+#include "aquila/source/generator/SquareGenerator.h"
+#include "UnitTest++/UnitTest++.h"
+#include <cstddef>
+
+SUITE(BlackmanHarrisWindow)
+{
+    TEST(ZeroAtEnds)
+    {
+        const std::size_t SIZE = 4;
+        Aquila::BlackmanHarrisWindow w(SIZE);
+        // 0.00006 has been manually calculated using:
+        // 0.35875 - 0.48829 * cos(0) + 0.14128 * cos(0) - 0.01168 * cos(0)
+        CHECK_CLOSE(0.00006, w.sample(0), 0.000001);
+        CHECK_CLOSE(0.00006, w.sample(SIZE - 1), 0.000001);
+    }
+
+    TEST(Multiplication)
+    {
+        const std::size_t SIZE = 1024;
+        Aquila::SquareGenerator generator(44100);
+        generator.setFrequency(1000).setAmplitude(500).generate(SIZE);
+        Aquila::BlackmanHarrisWindow w(SIZE);
+        auto result = generator * w;
+        // 0.03 = 0.00006 (see above) * 500 (amplitude)
+        CHECK_CLOSE(0.03, result.sample(0), 0.000001);
+        CHECK_CLOSE(0.03, result.sample(SIZE - 1), 0.000001);
+    }
+}
+
diff --git a/tests/source/window/BlackmanNuttallWindow.cpp b/tests/source/window/BlackmanNuttallWindow.cpp
new file mode 100644
index 0000000..54d1109
--- /dev/null
+++ b/tests/source/window/BlackmanNuttallWindow.cpp
@@ -0,0 +1,31 @@
+#include "aquila/global.h"
+#include "aquila/source/window/BlackmanNuttallWindow.h"
+#include "aquila/source/generator/SquareGenerator.h"
+#include "UnitTest++/UnitTest++.h"
+#include <cstddef>
+
+SUITE(BlackmanNuttallWindow)
+{
+    TEST(ZeroAtEnds)
+    {
+        const std::size_t SIZE = 4;
+        Aquila::BlackmanNuttallWindow w(SIZE);
+        // 0.0003628 has been manually calculated using:
+        // 0.3635819 - 0.4891775 * cos(0) + 0.1365995 * cos(0) - 0.0106411 * cos(0)
+        CHECK_CLOSE(0.0003628, w.sample(0), 0.000001);
+        CHECK_CLOSE(0.0003628, w.sample(SIZE - 1), 0.000001);
+    }
+
+    TEST(Multiplication)
+    {
+        const std::size_t SIZE = 1024;
+        Aquila::SquareGenerator generator(44100);
+        generator.setFrequency(1000).setAmplitude(500).generate(SIZE);
+        Aquila::BlackmanNuttallWindow w(SIZE);
+        auto result = generator * w;
+        // 0.1814 = 0.0003628 (see above) * 500 (amplitude)
+        CHECK_CLOSE(0.1814, result.sample(0), 0.000001);
+        CHECK_CLOSE(0.1814, result.sample(SIZE - 1), 0.000001);
+    }
+}
+
diff --git a/tests/source/window/CosineWindow.cpp b/tests/source/window/CosineWindow.cpp
new file mode 100644
index 0000000..4f7dac6
--- /dev/null
+++ b/tests/source/window/CosineWindow.cpp
@@ -0,0 +1,29 @@
+#include "aquila/global.h"
+#include "aquila/source/window/CosineWindow.h"
+#include "aquila/source/generator/SquareGenerator.h"
+#include "UnitTest++/UnitTest++.h"
+#include <cstddef>
+
+SUITE(CosineWindow)
+{
+    TEST(ZeroAtEnds)
+    {
+        const std::size_t SIZE = 4;
+        Aquila::CosineWindow w(SIZE);
+        CHECK_CLOSE(0, w.sample(0), 0.000001);
+        CHECK_CLOSE(0, w.sample(SIZE - 1), 0.000001);
+    }
+
+    TEST(Multiplication)
+    {
+        const std::size_t SIZE = 1024;
+        Aquila::SquareGenerator generator(44100);
+        generator.setFrequency(1000).setAmplitude(500).generate(SIZE);
+        Aquila::CosineWindow w(SIZE);
+        auto result = generator * w;
+        // 0.1814 = 0.0003628 (see above) * 500 (amplitude)
+        CHECK_CLOSE(0, result.sample(0), 0.000001);
+        CHECK_CLOSE(0, result.sample(SIZE - 1), 0.000001);
+    }
+}
+
diff --git a/tests/source/window/NuttallWindow.cpp b/tests/source/window/NuttallWindow.cpp
new file mode 100644
index 0000000..cb36d3c
--- /dev/null
+++ b/tests/source/window/NuttallWindow.cpp
@@ -0,0 +1,28 @@
+#include "aquila/global.h"
+#include "aquila/source/window/NuttallWindow.h"
+#include "aquila/source/generator/SquareGenerator.h"
+#include "UnitTest++/UnitTest++.h"
+#include <cstddef>
+
+SUITE(NuttallWindow)
+{
+    TEST(ZeroAtEnds)
+    {
+        const std::size_t SIZE = 4;
+        Aquila::NuttallWindow w(SIZE);
+        CHECK_CLOSE(0, w.sample(0), 0.000001);
+        CHECK_CLOSE(0, w.sample(SIZE - 1), 0.000001);
+    }
+
+    TEST(Multiplication)
+    {
+        const std::size_t SIZE = 1024;
+        Aquila::SquareGenerator generator(44100);
+        generator.setFrequency(1000).setAmplitude(500).generate(SIZE);
+        Aquila::NuttallWindow w(SIZE);
+        auto result = generator * w;
+        CHECK_CLOSE(0, result.sample(0), 0.000001);
+        CHECK_CLOSE(0, result.sample(SIZE - 1), 0.000001);
+    }
+}
+
diff --git a/tests/source/window/WelchWindow.cpp b/tests/source/window/WelchWindow.cpp
new file mode 100644
index 0000000..d4d41ec
--- /dev/null
+++ b/tests/source/window/WelchWindow.cpp
@@ -0,0 +1,29 @@
+#include "aquila/global.h"
+#include "aquila/source/window/WelchWindow.h"
+#include "aquila/source/generator/SquareGenerator.h"
+#include "UnitTest++/UnitTest++.h"
+#include <cstddef>
+
+SUITE(WelchWindow)
+{
+    TEST(ZeroAtEnds)
+    {
+        const std::size_t SIZE = 4;
+        Aquila::WelchWindow w(SIZE);
+        CHECK_CLOSE(0, w.sample(0), 0.000001);
+        CHECK_CLOSE(0, w.sample(SIZE - 1), 0.000001);
+    }
+
+    TEST(Multiplication)
+    {
+        const std::size_t SIZE = 1024;
+        Aquila::SquareGenerator generator(44100);
+        generator.setFrequency(1000).setAmplitude(500).generate(SIZE);
+        Aquila::WelchWindow w(SIZE);
+        auto result = generator * w;
+        // 0.1814 = 0.0003628 (see above) * 500 (amplitude)
+        CHECK_CLOSE(0, result.sample(0), 0.000001);
+        CHECK_CLOSE(0, result.sample(SIZE - 1), 0.000001);
+    }
+}
+