@book{27189,
	author = {Kupferbürger, Wilhelm,},
	title = {The travertine deposits near Port St. Johns,},
	publisher = {The Government printer,},
	year = {1935.},
	series = {South Africa. Geological Survey. Geological series. Bulletin,},
	address = {Pretoria,},
	note = {At head of title: ... Union of South Africa. Department of mines.}
}