Number 13 of our scholarly journal Holocaust Studies and Materials, published by the Polish Center for Holocaust Research of the Institute of Philosophy and Sociology of the Polish Academy of Sciences, is almost 900 pages of pioneering studies, materials, overviews, and editions of unknown primary sources. The main threads in this issue are two anniversaries. The first one is the 75th anniversary of Aktion Reinhardt, that is the extermination of Jews on Polish lands, and the other is the 70th anniversary of the establishment of the Jewish Historical Institute. We devote a range of texts to these topics. Same as articles about the structures of the Jewish Social Self-Help and the Holocaust research carried out by the Jewish Historical Institute during Stalinism, these texts present largely-unknown, new historical findings. This number is supplemented with texts about, for instance, the role of auxiliary formations in the Holocaust in Eastern Galicia and Lithuania and the results of the pioneering ethnographic research on memory conducted since the 1970s. It also contains reviews of newest publications and commentaries on current events.