Vol. 1; Curriculum Vitae, about 1889; Letters and reports from New Guinea, 1894-1901; private letters to inspectors of the RMG and his wife Dassel, 1895-1900; Vol. 2; Letters and Reports Reports from New Guinea, 1901-1913; Correspondence with Heinrich Helmich in his homeland, 1919-1944; Appointment as Houseparents in the Johanneum Gütersloh, 1922; "Some of New Guinea's Mission History", IN: Westfälisches Sonntagsblatt für Stadt u. Land, No. 38-40, 1928; "Die Kapelle zum Seelenfrieden", IN: Evangelisches Monatsblatt für Westfalen, No. 7 u. 8, 1928; obituary for Heinrich Helmich, obituary and letter of condolence, 1947; correspondence with Ida Helmich, née Winkelsträter, 1948; obituary for Ida Helmich, née Winkelsträter, 1951