update: add additional refs

Author: VsevolodX

lang/en/docs/tutorials/materials/specific/defect-point-interstitial-tin-oxide.md

@@ -143,7 +143,14 @@ To adjust the defect creation:
 
 ## References
 
-1. Togo, A., Oba, F., & Tanaka, I. (2006). First-principles calculations of native defects in tin monoxide. Physical Review B, 74(19), 195128.
+1. Togo, A., Oba, F., & Tanaka, I. (2006). First-principles calculations of native defects in tin monoxide. Physical Review B, 74(19), 195128. [DOI: 10.1103/PhysRevB.74.195128](https://doi.org/10.1103/PhysRevB.74.195128){:target='_blank'}.
+
+2. H. Wang, A. Chroneos, C. A. Londos, E. N. Sgourou & U. Schwingenschlögl, "Carbon related defects in irradiated silicon revisited" Scientific Reports 4, 4909 (2014).
+   [DOI: 10.1038/srep04909](https://doi.org/10.1038/srep04909){:target='_blank'}.
+
+3. Sutassana Na-Phattalung, M. F. Smith, Kwiseon Kim, Mao-Hua Du, Su-Huai Wei, S. B. Zhang, and Sukit Limpijumnong, "First-principles study of native defects in anatase Ti⁢O2", Phys. Rev. B 73, 125205 (2006).
+   [DOI: 10.1103/PhysRevB.73.125205](https://doi.org/10.1103/PhysRevB.73.125205){:target='_blank'}.
+
 
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