WIA GC/1881/2 | Sydow, Fritz to Warburg, Aby 03/01/1881 | New Year greetings; on his school in Lübeck; if Warburg meets Abel Ballen or Louis Dammert he... |
WIA GC/1882/8 | Sydow, Fritz to Warburg, Aby 01/02/1882 | elaborate apologies for not having written; asks what colours to use to paint greenish sea water |
WIA GC/1896/29 | Goldschmidt, Adolph to Warburg, Aby [1896] | he heard from Vöge that Warburg wanted to prepare for his university teaching qualification... |