WIA GC/10038 | Koetschau, Karl to Warburg, Aby 20/12/1892 | thanks him for a copy of his thesis; he enjoys reading it; on his research interests and projects... |
WIA GC/10252 | Warburg, Aby to Koetschau, Karl 25/08/1905 | he is pleased that Koetschau remembered their good relationship under their unforgettable teacher... |
WIA GC/10321 | Warburg, Aby to Koetschau, Karl [June 1906] | on [August] Schmarsow's information on the composition of the new committee of the International... |
WIA GC/10334 | Warburg, Aby to Koetschau, Karl 18/02/1906 | he regrets having missed Koetschau in Hamburg; is keen to be in touch with him; comments... |
WIA GC/10356 | Warburg, Aby to Schmarsow, August 13/06/1906 | forwards his voting papers; he has voted for [Paul] Clemen; asks why Adolph Goldschmidt's name... |