Correspondence, travelogues, working reports, Bukoba station reports, 1928-1931; "The Union Question in East Africa, 7 p., ms. by Heinrich Scholten, 1931; Memorandum of Bethel Mission Bukoba for the British Governor, 1931; New Beginnings in Bukobalande, 3 p., ms., 1931

1890-1930 in Ondjiva, Omupanda, Karibib, Swakopmund, Präses d. Ovambomission, estate see RMG 1.627; extensive correspondence, annual, station and travel reports, 1890-1936; travel report by Thusnelda Wulfhorst, née. Härlin, 1892; Private letters from August and Thusnelda Wulfhorst, née Härlin to Inspector Johannes Wilhelm Karl Spiecker, 1890-1900; "Osondahe", Monatsblatt d. Finnish Mission, May 1909; Correspondence with the German Consulate and Portuguese authorities concerning property claims in Omupanda, 1920-1927; Obituary for August Wulfhorst by Johannes Georg Heinrich Olpp, 1936; Correspondence with his 2nd wife, Johanna Wulfhorst, née Härlin, 1937-1956