Kartei Leipziger Familien, page A_00569: Duncker Gustav Heinrich (B. u. Kaufmann)
Kartei Leipziger Familien
You can report transcription errors here. (It is only a transcription error if, for example, the source reads "Wilhelm" but "Wihlem" was transcribed. It is not a transcription error if the source reads "W." and you suspect it should be "Wilhelm".)