https://jamestown.org/program/the-realities-of-russian-military-shipbuilding-part-two/
https://www.ng.ru/armies/2021-10-07/2_8272_fleet.html
https://jamestown.org/program/the-realities-of-russian-military-shipbuilding-part-one/
https://jamestown.org/program/clashes-intensify-between-moscow-and-circassians-on-key-issues/
https://www.rbc.ru/newspaper/2021/10/04/61571a279a79478e0bc0b011
http://www.kasparov.ru/material.php?id=614CB672DC70D
https://jamestown.org/program/russias-military-boosts-electromagnetic-spectrum-capability/