Rotterdam Missionsgesellschaft; R. Ledeboer, secretary, sends writings and asks for return delivery, 1825; list of needs of a missionary to be sent out, equipment, travel expenses and costs for ongoing maintenance in Africa, 1829; Ledeboer sends 12 Dutch-speaking missions. Bibles as a gift, 1829; Ledeboer requests information about Wilhelm Wilhelmi, 1830; Ledeboer requests trained missionaries for East India, 1830; Ledeboer requests documents to obtain a residence permit for RMG missionaries in Borneo and Java, 1834; Ledeboer requests information about Philipp Wilken, 1837; Domine van Rhyn writes about himself and his family, offers to take packages to Dutch India, 1845;

Inspector 1930-1945; The Mission in Dutch India, 1 p., ms., 1934; Remarkable figures from Dutch India, 1 p., ms. 1934; Correspondence, inter alia with Reichsschrifttumskammer, Berlin, 1934-1940; contributions to an evangelical missionary teaching, 3 p., ms. 1938; Mission und Volkstum, 3 p., ms., 1938; Remarks on the situation of the mission in summer 1939, 2 p., ms., 1939; Curriculum Vitae, 1940; Report Delius about his arrest in Halle, 1941; Correspondence, 1941-1945; Die Batakkirche in der Feuerprobe, 6 p., ms., 1944; Correspondence with family, i.a. about the fate of Delius who was missing, 1946-1970