https://www.gazeta.ru/army/2018/12/02/12080227.shtml
http://www.kasparov.ru/material.php?id=5C02D70A8ED1D
http://nvo.ng.ru/armament/2018-11-30/1_1024_battle.html
https://www.inopressa.ru/article/26Nov2018/dailybeast/spy.html
http://www.rosbalt.ru/business/2018/11/26/1748828.html
“Natural causes” can’t be ruled out. But those include stress, and there’s no doubt Gen. Korobov of the G(R)U was under a lot of that.
https://www.thedailybeast.com/inside-the-mystery-of-the-dead-russian-spy-chief
https://www.inopressa.ru/article/23Nov2018/handelsblatt/kaspersky.html
http://www.ng.ru/economics/2018-11-23/5_7446_nedra.html
http://www.dsnews.ua/world/smert-nachalnika-gru-kak-putin-naryadilsya-v-nikolaya-i-22112018220000