https://www.gazeta.ru/army/2017/12/30/11585354.shtml
https://www.gazeta.ru/business/2017/12/30/11583752.shtml
Download the Report
https://www.csis.org/analysis/russian-speaking-foreign-fighters-iraq-and-syria
https://www.radiosvoboda.org/a/28945900.html
https://www.radiosvoboda.org/a/28945769.html
https://www.gazeta.ru/army/2017/12/28/11568260.shtml
https://www.kommersant.ru/doc/3512383
http://www.rosbalt.ru/russia/2017/12/29/1672008.html
https://ru.krymr.com/a/28943727.html