ElMondoHummus
0.25 short of being half-witted
Refutation of many arguments, including the ones used by Walter Sanning (a researcher sourced in MaGZ's link):
"Holocaust Denial: Demographics, Testimonies and Ideologies", John C. Zimmerman.
Also, some info regarding the "emigration" stats listed by Carl Nordling (another researcher sourced in MaGZ's link):
http://www.nizkor.org/qar-complete.cgi (Start reading at question 15 on that page, then continue onward. This isn't a direct refutation of Nordling, BTW; rather, it's context for Nordling's figures.)
Before anyone starts giving too much credence to revisionist studies trying to recast the numbers killed in the Concentration Camps, let's understand that the bulk of proof for the 6 million dead come from the Nazi's themselves. There's hard documentation too, not only human testimony. As one, small example, see some of the evidence that contributed to the Treblinka numbers:
http://www.nizkor.org/ftp.cgi/camps/aktion.reinhard/treblinka/
No, of course there's not some master doc that says "We executed 300 Jews yesterday, 400 today...". But there's other information; transportation documents, for example, enumerating the number transported in. Etc. It has to be put together, like any complex narrative. Regardless, I'd take counts from documentation and witness testimony validated during the Nuremberg trials over any statistical analysis done after the fact by people with a pre-existing interests in historical revisionism, like the two in the link MaGZ provides.