Six letters from Dar-es-Salaam, 1895-1896; "A "Eben-Ezer of the Lutindi lunatic asylum in western Usambara, history of Lutindi for the 25th anniversary recorded by Wilhelm Bokermann, 34 p., ms., 1929; letters of thanks Ronicke to donors of the Nazareth Missionary League; death announcement for Friedhelm Bokermann, died 1944; correspondence with Wilhelm Bokermann, 1929-1946

Letters and correspondence, 1898-1909; Personal correspondence by Dr. Philipps and a letter by Pastor von Bodelschwingh, 1911, and a newspaper clipping, 1912; family letters, 1914-1919; testimony for Pastor Rösler, 1921; letters from African Christians to Rösler "New Letters from Usambara, 1922

Letters and diary reports from Becker & Döring