The Gypsy camp book
When prisoners could not immediately pass evidence to the outside world, they concealed it inside the camp. This is what happened with the two record books from the Gypsy family camp, containing the camp numbers, nationality, date and place of birth, date of death, relegation to the penal company, and other information on almost 21 thousand Roma and Sinto people incarcerated there.
In July 1944, three Poles, Tadeusz Joachimowski, Ireneusz Pietrzyk, and Henryk Porębski sneaked the record books out of the camp offices and buried them. After the war, Joachimowski pointed out the burial spot. The books were conserved, and their contents published in 1993.