KEO-Archiv A 89/7 (ms)

Brief August Kuth an die Choralion Company, Berlin, vom 22.11.1909

KEO-Archiv A 89/8 (ms)

Brief Choralion Co.m.b.H., Berlin, an DM vom 24.11.1909

KEO-Archiv A 89/9 (ms)

Brief August Kuth an die Firma Choralion & Co, Berlin, vom 30.06.1910