Forms part of the Claims Conference International Holocaust Documentation Archive at the United States Holocaust Memorial Museum. This archive consists of documentation whose reproduction and/or acquisition was made possible with funding from the Conference on Jewish Material Claims Against Germany. Source of acquisition is the Archiwum Akt Nowych, Warsaw, Sygn. 231 (old); Sygn. 1349 (new).The first part of Landau's manuscript (from Sept. 1939 to Dec. 1942) was held by Mr. and Mrs. Hessen. It was put in a metal box and buried on the grounds of the Free Polish University in Warsaw, Poland, at Opczewska Street. The rest of the manuscript and a typewritten copy were stored in the cellar of Landau's apartment. Soon after World War II ended, these papers were retrieved and handed over to Landau's relatives. Part of the diary buried on the grounds of the Free University in Warsaw has never been recovered. The records of Syg. 231 were kept until 1990 in the Central Archives of the Komitet Centralny Polskiej Zjednoczonej Partii Robotniczej - KC PZPR (Central Committee of the Polish United Workers' Party) and subsequently in the Archiwum Akt Nowych in Warsaw (Central Archives of Modern Records). The United States Holocaust Memorial Museum Archives received the collection via the United States Holocaust Museum International Archives Project in Jan. 2002.