Jewish Historical Institute in Warsaw, Holocaust Survivor Testimonies (coll. 301), Marta Klein Testimony (301/12). Original in Polish.
Testimony of Marta Klein on the actions against Jews in Vilnius and Białystok and deportations to Treblinka, her escape en route to the camp, her rescue by a Pole, Czuliński, and the arrest of her son and his protector after their betrayal.
The Wiener Library for the Study of the Holocaust and Genocide, Persecution of Jews in Poland: reports and statements (coll. 532), 114. Original in Yiddish.
Testimony of 24-year-old journalist Dovid M. from Brok on the destruction of Brok and a massacre of 38 Jews taking place on the same day.
