Letters from local Christians by J. F. Hein, Evangelist, 1905; Telegrams (including 1 "optical telegram"); Hypothekenangelegenheit Charles Ritter, 1903-1906; detailed account of construction and equipment e. Ochsenwagens, 1906; map sketch with travel route to Ovamboland, 1906; Letters to Johannes Wilhelm Karl Spiecker from the Heimatleitung, 1906; Reiseerlaubnis d. German authorities in Outjo, 1906

Korrespondenz, 1930-1969; Vow of Deputation, 1933; Arbeitsberichte, 1930-1932; Zwei Briefe von einheimischen Christen (Bitte um Trombone), 1931; Tagebuchblätter aus dem Gemeindeleben in Kigarama, 1932; "Komm u. see How I Die, 1933; "Magambo - small pictures from a large community, 1934; "About the Origin of Wamara - narrated by an old Kisibamann, 1934; "We Go There and Walk, 1935; "From Community Life in Kigarama, 1936; "A Royal Mother in Hayaland, 1937