Errata
Soviet WW2 Archives
Although the Central Archives of the Russian Ministry of Defense (TsAMO) have been closed to western researchers, previously released archival materials have been published and are available online through the Electronic Library of Historical Documents:
https://docs.historyrussia.org/ru/nodes/1-glavnaya.
The website is in Russian, but most browsers successfully convert the page into English through their translation feature in the address bar.
The website features published Soviet archival material. Every document is fully transcribed. The text can be copied and pasted into a translation tool. If you do not know the name of the specific book you are looking for, the best way to browse is their “Historical period” page:
https://docs.historyrussia.org/ru/indexes/types/45
Their collection of books is divided into separate periods, all the way from Ivan the Terrible to the Cold War. The interwar period and the Second World War are covered in periods 23 through 30.
Recommended Reading
Naumov’s “1941 god” contains documents in the leadup to Operation Barbarossa, including Soviet war and mobilization plans, in 2 volumes:
https://docs.historyrussia.org/ru/nodes/91260-1941-god-v-2-kn
The 1990s collection, “Russian Archives: The Great Patriotic War” contains a wealth of documents from the Second World War, organized by command authority (Stavka, general staff, etc.) and key battles (Moscow, Kursk, etc.).
https://docs.historyrussia.org/ru/nodes/134706-russkiy-arhiv-velikaya-otechestvennaya
Another valuable resource is the “Collection of combat documents of the Great Patriotic War” published in the decade following the Second World War: