Books like The Hidden Holocaust? by Günter Grau

This is about a suffers of victims of Nazi invasion during World War 2 and Holocaust

An in‑depth examination of how the Nazi regime systematically persecuted homosexuals—law, imprisonment, and post‑war treatment—tracing the arc from 1933 through the Holocaust to the aftermath.

Originally published in German, Erika Thurner's National Socialism and Gypsies in Austria is the ground-breaking study of Nazi policy toward Gypsies during the Third Reich. As noted in the foreword, although Jews were the major target of the Nazis, others were also marked for extermination. Indeed, of the groups targeted by the Nazis, only Jews and Gypsies were killed indiscriminately and tribally, that is, by the gassing of entire family groups of men, women, and children. Of the eleven thousand Gypsies living in Austria at the start of the war, only three thousand survived Nazi persecution. In the first English translation of this important work, Gilya Gerda Schmidt makes available Thurner's investigation of Camps Salzburg and Lackenbach, the two central areas of Gypsy persecution in Austria. This English translation has also been expanded, with a new study of Camp Salzburg, an updated bibliography, and numerous photographs, which were not included in the German edition.

Henry Friedlander details how the Nazi "euthanasia" program against handicapped and disabled people became the prototype for the systematic extermination of Jews and Roma during the Holocaust.