North America continued
Paul A. Opler, Harry Pavulaan, and Ray E. Stanford, 1995. Butterflies of North America, Northern Prairie WIdlife Research Center Home Page:
<http://www.npwrc.org/resouce/distr/lepid/bflyusa.htm>

Robert Michael Pyle, 1984. The Audubon Society Handbook for Butterfly Watchers. Scribners ISBN 0684181517 $17.95 (How to look for and enjoy butterflies, how to study, watch, count and teach about butterflies.)

James A. Scott, 1986. The Butterflies of North America: A Natural History and Field Guide. Stanford University Press, Palo Alto. 583 pp. ISBN 0-8047-1205-0

Ernest M. Shull, 1987. The Butterflies of Indiana. Indiana University Press, Indiana Academy of Science, Indianapolis. ISBN 0235312922 $30.00 (Comprehensive butterfly book with 50 color plates that serves Illinois as well as Indiana.)

Donald Stokes, Lillian Stokes, and Ernest Williams, 1991. The Butterfly Book: An Easy Guide to Butterfly Gardening, Identification, and Behavior. Little Brown & Co. ISBN 0316817805 $12.95 (Field guide by recognized writers on natural history.)

Hamilton Tyler, Keith S. Brown, Jr., and Kent Wilson, 1994. Swallowtail Butterflies of the Americas. Scientific Publishers, Gainesville. 376 pp. ISBN 0-94-5417-90-X (also available in paperback).

Latin America
Bernard D’Abrera, 1984. Butterflies of South America. Hill House, Ferny Creek, Australia. 256 pp.(paperback) ISBN 0 9593639 2 0

Bernard D’Abrera, 1981. Butterflies of the Neotropical Region. Part 1. Papilionidae and Pieridae. Lansdowne Editions, East Melbourne.

Philip J. DeVries, 1987. The Butterflies of Costa Rica and their Natural History. Papilionidae, Pieridae, Nymphalidae. Princeton University Press, Princeton. 327 pp., 50 plates. 1997. Vol. 2, Riodinidae. 368 pp.

Hamilton Tyler, Keith S. Brown, Jr., and Kent Wilson, 1994. Swallowtail Butterflies of the Americas. Scientific Publishers, Gainesville. 376 pp. ISBN 0-94-5417-90-X (also available in paperback).