One subject I have almost never found any reading material on was the treatment and fate of the hundreds of thousands ( millions? ) of German, Romanian, Japanese, Italian, Spanish POWs in Russia.
An almost forgot subject. I know about the 1955 return of many German POWs that Adenauer pulled off, general conditions of the camps and such but real details are greatly lacking.
I did read an old congressional hearing booklet with testimony from Russian Jews who claimed there were still German POWs in Russia during the 1970s. These Jews were in the gulag system themselves. They further claimed they were held on Sakhalin Island, were SS or nazis and medical / radiation experiments were common.
They further claimed a few Eskimos were in the camps, many Japanese too.
But other testimony also included the Russians disposing of prisoners with railroad trains that went off unfinished bridges. So, I figure a fair amount of the testimony was what these people had heard rather than seen.
But one has to figure the numbers of Japanese the Russians took toward the end of the war must have been staggering: the Soviets steam rolled the Japanese army. Was always surprised the Japanese didn't break out the chemical / biological weapons vs the Russians. Heavens knows they had them but the ton and were experts in using them.
Have you ever read Gulag Archipeligo by Alexander Solzhinitsyn? Great detail about the camps and biographies of some of those imprisoned.