List of sources:
Hall, A.L. Bibliography of South African geology to the end of 1920. Pretoria: Geological Survey, Memoir No. 18, 1922.
Hall, A.L. Subject index to the literature on the geology and mineral resources of South Africa. Pretoria: Geological Survey, Memoir No. 22, 1924, p. 10.
Rhodesia Scientific Association. Proceedings, 1899-1901, Vol. 1 (pp. 3, 4, 24-29), Vol. 2 (pp. 55, 92).