1. Gilinskii, Ya.M., Demography of “prisoners,” Demoskop Weekly, 2009, nos. 361–362. http://demo-scope.ru/weekly/2009/0361/s-map.php . Cited October 5, 2013.
2. GULAG: ekonomika prinuditel’nogo truda (Gulag: Economics of Compulsory Labor), Borodkin, L.I., Khlevnyuk, O.V., and Gregory, P., Eds., Moscow: ROSSPEN, 2008.
3. The data of Russian census of 2010. http://www.perepis-2010.ru/ . Cited October 5, 2013.
4. The history of the Penal Colony no. 10 of the Office of the Federal Penitentiary Service in the Ulyanovsk oblast. http://73.fsin.su/structure/ik-10.php . Cited October 5, 2013.
5. The history of the Medical-penal institution no. 7 of the Office of the Federal Penitentiary Service in the Astrakhan oblast. http://30.fsin.su/structure/detail.php?ELEMENT-ID=33807 . Cited October 5, 2013.