Gruesome Harvest is a book by Ralph Franklin Keeling that was the first of its kind. It makes a strong dual moral and geopolitical case for the good treatment of Germans after the war. It did so in 1947 during the Morgenthau Plan, when most Americans had no idea what was happening in Germany, and certainly had no idea of the level of criminal mistreatment being enacted on the German people.
The author notes the three primary components of a healthy economy: land, labor, and capital, and intends to demonstrate that all three were being destroyed in Germany. The author notes the sheer destruction inflicted on Germany during the war itself - how its industries were destroyed and populations annihilated in brutal bombing campaigns over cities and tank drives through their country.
The author tells us that the Germans were subjected to racially-based expulsions in Poland, Czechoslovakia, and Hungary, authorized at the Potsdam Conference.
Here is a video of the expulsion:
We see an immediate parallel to the previous book I posted about, The Years of Great Silence. The expulsion of ethnic Germans from these countries differs only in the sense that some were allowed to go to Germany rather than be enslaved by the Soviet Union, although many millions were subjected to this fate (p 9-14).