Chełmno extermination camp
The Grojanowski Report is an eye-witness account about atrocities in the Nazi Chełmno extermination camp, written in 1942 by Polish-Jewish escapee from the camp, Szlama Ber Winer (also known incorrectly as Szlawek Bajler), under the pseudonym of Yakov (or Jacob) Grojanowski. Szlama Ber Winer managed to make his way from Chelmno to the Warsaw Ghetto and gave detailed information about his week-long experience with the "Sonderkommando" at that death camp to the Ghetto's Oneg Shabbat group, headed by historian Emanuel Ringelblum.