References:

Borror, Donald, J. Norman F. Johnson and Charles A. Triplehorn. An Introduction to the Study of Insects. Sixth Edition. Harcourt Brace College Publishers, New York, New York 1989

Edwards, in Brower, James E. et al. Field and laboratory methods for general ecology. McGraw Hill: Boston. 1999

Gonzalez, Eugenio. Director of the Office of Tropical Studies at Palo Verde National Park, Costa Rica. Lecture on the History of Costa Rican Land Conservation and Land Management Practices. July 13, 2001.

Janzen, Daniel H. Costa Rican Natural History. The University of Chicago Press, Chicago, Illinois. 1983

Stiles, Gary, and Skutch, Alexander F. A Guide to the Birds of Costa Rica. Comstock Publishing Associates, Ithaca, New York 1989

Zar, Jerrold H. Biostatistical Analysis. Prentice Hall: New Jersey. 1999

EPA Rapid Bioasessment of Streams. Http://www.epa.gov/