@book{39716,
	author = {Ehrlich, Paul R. and Ehrlich, Anne H.},
	title = {Population, resources, environment},
	publisher = {W. H. Freeman},
	year = {[1972]},
	series = {A Series of books in biology},
	address = {San Francisco},
	edition = {2d ed.},
	note = {Third ed. published in 1977 under title: Ecoscience.}
}