List of sources:
Chemical and Metallurgical Society of South Africa. Proceedings, 1899, Vol. 2, list of members.
Chemical, Metallurgical and Mining Society of South Africa. Proceedings, 1902-1903, Vol. 3, p. 378: Members killed or died on active service.
FamilySearch: G Schmitz-Dumont. https://www.familysearch.org/ark:/61903/1:1:6VRF-2GFP?lang=en
Geological Society of South Africa. Transactions, 1896, Vol. 2.
Hall, A.L. Bibliography of South African geology to the end of 1920. Pretoria: Geological Survey, Memoir No. 18, 1922.
National Automated Archival Information Retrieval System (NAAIRS). http://national.archives.gov.za/naairs.htm Documents relating to "Schmitz-Dumont".
Pretorius, D.A. The depositional environment of the Witwatersrand goldfields: A chronological review of speculations and observations. Minerals Science and Engineering, 1975, Vol. 7(1), pp. 18-47.
Staats-Almanak der Zuid-Afrikaansche Republiek, 1898.
Zuid-Afrikaansche Republiek. Rapport van het Hoofd van Mijnwezen met bijgevoegd rapport van den Staatsmijningenieur over het jaar 1896. Pretoria: Staatsdrukkerij, 1897.