https://www.russiansystema.co.uk/martial-arts/spetsnaz-training
https://www.oxfordresearchgroup.org.uk/blog/spetsnaz-an-interview-with-mark-galeotti
https://www.wearethemighty.com/history/a-green-beret-describes-spetsnaz?rebelltitem=1#rebelltitem1
https://www.thesun.co.uk/news/7368052/russia-spetsnaz-sergei-skripal-training/
https://incredible-adventures.com/russian_ops1.html
https://www.theglobeandmail.com/news/world/russias-most-notorious-army-hazing/article20405997/
https://www.rferl.org/a/1065380.html
https://www.nytimes.com/2006/08/13/world/europe/13hazing.html
https://www.aljazeera.com/indepth/opinion/russian-special-operations-forces-idlib-190828144800497.html
https://vpk-news.ru/news/35417#