The following quote is taken from a Professor Mark's scathing review of Raul Hilberg's 1961 book The Destruction of the European Jews, published in the previously CPUSA affiliated Jewish Currents, April 1963.
The review, which was originally written in Yiddish; published in Poland, and four times the length of the Jewish Currents' version, mainly focuses on attempts to refute Hilberg's hypothesis of "Jewish passivity" during the Holocaust.
In Auschwitz, according to Hilberg, a million Jews perished, whereas, in fact the number of Jews destroyed there was a least twice as great.
The sum total, Hilberg says, of Jews destroyed was 5,100,000 (pp. 639, 767). On what basis Hilberg casts doubt on the accepted minimum of 6,000,000—which is based on compilations made at a number of scientific institutes—is unknown to us. A man who had pored for 10 years over Nazi documents did not find it necessary to research this figure himself, but uncritically accepts the widely-doubted figure given by the English author Reitlinger, who also pored over Nazi documents but is far from accurate. Without any basis and for no reason at all, Hilberg reduced the actual total of Jewish victims.