Documentation regarding the activities of the JDC organization and the Comite de Defense des Juifs (CDJ) underground organization on behalf of the Jews in Belgium, and documentation regarding the situation of the Jews in Belgium during the war and after, 1942-1945 - Correspondence between Saly Mayer, the JDC organization representative in Switzerland, and Adolph Nykerk, regarding the activities of his brother Benjamin Nykerk on behalf of the persecuted Jews in Belgium, in the context of his activities in the Comite de Defense des Juifs (CDJ) underground organization; the financing of the activities was transferred to Belgium with the help of Marcus Cohn, a Zionist lawyer in Basel; - Report regarding the CDJ organization's activities in Belgium, 01 January 1944; - Report regarding the situation of the Jewish population in Belgium, September 1942-December 1943; - Report by the Hechalutz movement regarding the situation of the Jews in Europe and, in particular, in Belgium, 09 February 1944; - Documentation regarding the results of the negotiations held between Saly Mayer and Benjamin Nykerk, regarding cooperation on the subject of relief to Jews in Belgium, 23 February 1944; - Correspondence between Saly Mayer and M. Elion, a cousin of the Nykerk brothers, regarding relief to Jews in Belgium; - Reports prepared by the CDJ organization in Belgium for the World Jewish Congress in Geneva, regarding the situation of the Jews in Belgium after the liberation, October 1944; - Report by the CDJ organization regarding its expenses on behalf of the persecuted Jews in Belgium, 03 November 1944; - Report regarding Belgium, by Theodora Dreifuss in Zurich, 31 December 1945.