Boiarov, V., M. Larkin, K. Legkykh, O. Melkovskyi, and M. Hromova. “Ways of Prevention of Funding for Youth Informal Groups of Extremist Orientation”. Amazonia Investiga, Vol. 8, no. 24, Nov. 2019, pp. 479-83, https://www.amazoniainvestiga.info/index.php/amazonia/article/view/1007.