@book{28229,
	author = {Wickman, Frans E.},
	title = {A graph for the calculation of the age of minerals according to the lead method,},
	publisher = {Kungl. boktryckeriet, P.A. Norstedt & söner,},
	year = {1944.},
	series = {Sweden. Sveriges geologiska undersökning. Ser. C. Avhandlingar och uppsatser.},
	address = {Stockholm,},
	note = {At head of title: Sveriges geologiska undersökning ...}
}