During 1967 officers of the Institute too samples at three faces in the Dumbe colliery, situated approximately 2 miles (3 km) to the south east of Paulpietersburg, Natal.
Reference:
Boshoff, H. 1972. Survey report No. 377 on Three face samples taken at Dumbe colliery Paulpietersburg district Natal. http://hdl.handle.net/10204/12854 .
Boshoff, H. (1972). Survey report No. 377 on Three face samples taken at Dumbe colliery Paulpietersburg district Natal Retrieved from http://hdl.handle.net/10204/12854
Boshoff, HP Survey report No. 377 on Three face samples taken at Dumbe colliery Paulpietersburg district Natal. 1972. http://hdl.handle.net/10204/12854
Boshoff H. Survey report No. 377 on Three face samples taken at Dumbe colliery Paulpietersburg district Natal. 1972 [cited yyyy month dd]. Available from: http://hdl.handle.net/10204/12854