Sanning's account goes like this: before and during the German invasion of the USSR, Stalin deported some 25 to 30 million Soviets to Siberia....
That reference was questioned. Here is the citation info. from Sanning's book: 'The Dissolution of Eastern European Jewry'.
on page 73 he states:
...one may state that the people evacuated and deported to the Urals and Siberia - including the mobilized men - must have numbered more than 25 million; of these over, 15 million came from the cities in the occupied Soviet areas.
Sanning arrives at this number via various sources given in chapter three, and specifically summarizes the numbers on pages 72-73. Sanning uses German sources, Russian sources, American sources, and Jewish sources.
The point for our purpose is to demonstrate that alleged 'missing persons' (read: 'exterminated'), blamed upon the Germans, weren't really missing/exterminated at all.