the University of Amsterdam. Photographs from the Siboga expedition can be found in the Tropenmuseum, the Special Collections of the University of Amsterdam and the Artis Bibliotheek, at the same university.
ref: UvA-Artis Sibog 300.065
https://commons.wikimedia.org/wiki/File:UvA-BC_300.065_-_Siboga_-_Dongala.jpg
Copyright: Public Domain