HHow to Know the ButterfliesHow to Know the Butterfliesde Paul R. EhrlichEdiciones (1)How to Know the Butterflies (1961)WCB/McGraw-Hill · ISBN 9780697048219Más obras de Paul R. EhrlichDDie BevölkerungsbombeDie BevölkerungsbombeExtinctionHHow to be a survivorHow to be a survivor