GERHARDT, J. Edmund Siemers: Unternehmer und Stifter. [s.l.] : Hamburg University Press,2014. v. Band 16 DOI: 10.15460/HUP.MFW.16.150. Disponível em: https://hup.sub.uni-hamburg.de/oa-pub/catalog/book/129. Acesso em: 29 jan. 2023.