Earthquakes in South Africa,
by L. J. Krige and B. D. Maree.
- Pretoria, Govt. Printer, 1951.
- 14 p. fold. map. 24 cm.
- South Africa. Dept. of Mines. Geological series. Bulletin no. 20 .
- Geological series. Bulletin (South Africa. Geological Survey Division) ; no. 20. .