Autore:Heinrich Berghaus

- ↑ 1,0 1,1 Gemeinsame Normdatei
- ↑ Bibliothèque nationale de France
- ↑ SNAC
- ↑ 4,0 4,1 Biografisch Portaal
- ↑ 5,0 5,1 KNAW Past Members
- ↑ Brockhaus Enzyklopädie
- ↑ National Library of Israel Names and Subjects Authority File
- ↑ Fonte