@book{26193,
	author = {Wybergh, Wilfrid John,},
	title = {The coal resources of the Union of South Africa ...},
	publisher = {The Government Printing and Stationery Office,},
	year = {1922-28.},
	series = {South Africa. Geological Survey. Memoir},
	address = {Pretoria,},
	note = {At head of title: Union of South Africa. Dept. of mines and industries.}
}