Saurykova, Z. S., and S. B. K. R. L. A. A. M. B. Zhaskairat T. Yernazarov. “Repressive Policy of Kazakhstan in the 20-30s of the 20th Century”. Opción, Vol. 36, no. 91, 1, pp. 1522-38, https://www.produccioncientificaluz.org/index.php/opcion/article/view/32512.