Letters from Joel Kibera to Bertha Johanssen, 1930-1932; letters from Joel Kibera to Ernst Johanssen and Curt Ronicke, 1930-1933; letters to Ernst Johanssen from various senders, including by Alexander Kielima, Josua Hermas, G. A. Kajejero, Jakobo Ngombe, Kamara Kalembo, Andrea Kyaishozi, Petero Habugumisha, Yakobo Kajuma, Ernest Kalembo, Yuhi Musinga, Kamanzi, Saulo Kagya, Yusufu Hiliyai, and many more.., 1927-1933; Letters from local Christians translated into German, among others by Joel Kibira, Josua Hermas, Jakobo Ngombe, Lukas Sefu, Andrea Kajejero, Abel Mutungudja, Samuel Stepke, 1922-1934; transcriptions and replies, 1922-1934; travel diaries "Safari ya Bukoba Heft I u. II, 1929-1930; 2 booklets Grammatische Übungen, 1932

Letters to Curt Ronicke from various senders, including Andrea Kyaishozi 1930, Andrea Kajejero 1932, Daniel Muhingo 1933, Joel Kibira 1929, 1930 and others. 1935, Job Kuyonga 1936, Elisabeti Nabuye, Ibwera 1937, Joshua Hermas 1935 and 1938, Emili Kilimasti 1942, Stanislaus Karumuna 1949, Jonathan Karoma, Kanyangereko 1949, Jakobo Ngombe, Lumwe 1949 u. 1950, Matia B. Lutosha 1950, Paulo Nkinda Mazimu, Bumbuli 1950; "The Journey to Rwanda by Joel Kibira, 1930; The Journey to Bukoba by Jakobo Ngombe, 1930; Letter from a Haya woman (Nyabwolo) telling about her life, 1933; Life Story of the Warden in Kamatchumu, Mfizi, 1936; Baptismal Address by Hyob K.., Mlalo 1937 and Himmefahrtsan-sprache, 1933; speech by Andrea Kajejero, 1937; joint letter from community elders

Personalbogen, 1930; curriculum vitae, 1930; Tropenzeugnis für Elisabeth Hege, née Müller, 1930; Dienstanweisung, 1931; correspondence, circulars and reports, 1930-1970; 2 letters from local Christians, 1932; "Kigaramas große Festtag, Baptism of 207 heathens, 1933; "Mutter Bukoba u. her children, 1936; "In Service to the Church in Ihangiroland, 1936; "Bethel's Service to the Rwandan People in Buhaya, 1936; Medical testimonies for Robert Hege and his family: 1936, 1940 and 1963; "Diakonie im Missionsdienst, 1941; accounts, salary questions, loans, etc., 1963-1967

Correspondence (s.a. M 270), 1896-1897; correspondence, reports, diary excerpts (s.a. M 273) from 1906; Easter sermon in Hohenfriedeberg, 1914; "Vom Schulbau in Mutindili, 1914; Letters by Elfriede Kraemer (stepdaughter of Hosbach) to the Trittelvitz couple, 1912-1914; Hosbach's letters from prisoner of war in Egypt, 1917-1919; "Paulo Shempahila - Lebensbild eines einheimischen Gehilfen, 1919; 3 Songs in Swaheli (Text u. Sheet music by Martha Hosbach), 1927; Letters and reports by Martha Hosbach from 1926; "Die Schule von Kijunga von Josua Hermas, translated by Wilhelm Hosbach, 1932; Jahres-, Konferenz- u. Schulberichte von Bukoba, 1932; Gutachten zur Wasserversorgung in Kigarama, 1932; draft: "Integration of the mission into the German Protestant Church of Knak; "Neue Ordnung für die Missionsarbeiter der Bethel-Mission, 1933; "Ein Wort Dankbarer Erinnerung an Frau Künzel, 1934; Correspondenz während des 2. 1939-1949; letter from an African teacher to Wilhelm Hosbach, 1949; correspondence with the Hosbach couple at home, 1949-1961; obituary for Martha Hosbach, widowed Kraemer, née Wegener; obituary, obituary and memories of Wilhelm Hosbach, 1964