diff --git a/TreeTools-source b/TreeTools-source
new file mode 160000
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--- /dev/null
+++ b/TreeTools-source
@@ -0,0 +1 @@
+Subproject commit cb8c32fd1b3631ac4966e0377b884fb1e4a375c4
diff --git a/vignettes/using-distances.Rmd b/vignettes/using-distances.Rmd
index 7a8885cfe..e1e7b5940 100644
--- a/vignettes/using-distances.Rmd
+++ b/vignettes/using-distances.Rmd
@@ -28,7 +28,7 @@ Selecting an appropriate normalizing constant may require careful consideration
 of the purpose to which a tree distance metric is being put.
 
 The default normalization behaviour of each function when `normalize = TRUE` is
-listed in the [function reference](../reference/index.html), or can be viewed
+listed in the [function reference](../reference/00Index.html), or can be viewed
 by typing `?FunctionName` in the R terminal.
 
 ### Nye _et al._ tree similarity