Letters, reports, invoices, 1901-1910; So-called "Burensache, i. e. the employment of two Boers from Transvaal, father and son of Folker, who could not return to their homeland, 1902-1903; "Baptism of the first fruits of Gombero, December 1906; Plan of the Mission House in Gombero (Digo), 1907; Call to Organize a German Protestant Church in Tanga u. in the hinterland, printed flyer, 1909; A copy of the "Usambara-Post with an essay by Delius about "Die deutsche evangelische Kirchengemeinde von Tanga u. Hinterland vom September 1909

Correspondence from Rorarius, accounts, etc.; "Christmas Greetings from Bethel, 4 p., printed, December 1935; flyer "We have promised our help from Friedrich von Bodelschwingh with an essay "Das rufende Land (Usambara) von Rorarius, September 1935