WIA GC 1930/1459 | Bing, Gertrud to Hertz, Wilhelm [?] 20/08/1930 | forwards a written request regarding the library that Hertz might be better equiped to answer |
WIA GC 1930/1460 | Bing, Gertrud to Hertz, Wilhelm 11/11/1930 | |
WIA GC 1931/1218 | Hertz, Wilhelm to Bing, Gertrud 20/01/1931 | |
WIA GC 1931/1219 | Bing, Gertrud to Hertz, Wilhelm 02/02/1931 | |
WIA GC 1932/1266 | Bing, Gertrud to Hertz, Wilhelm 02/02/1932 | |