American Ornithologists' Union. 1998.
Check-list of North American birds: 7th edition
American Ornithologists' Union. Allen Press, Lawrence, Kansas. 829 pgs.
(ISBN 1-891276-00-X)

Araya M., Braulio and Guillermo Millie H. 1998.
Guía de campo de las aves de Chile
Editorial Universitaria. Santiago de Chile. Pgs 146-153.
(ISBN: 956-11-1236-1) (Spanish)

Ardeola: Revista Ibérica de Ornitología. 1971.
Volumen Especial. 1971. 673 pgs.
Organo de la Sociedad Española de Ornitología (Spanish)

Barlow, Clive and Tim Wacher. 1997.
A field guide to birds of the Gambia and Senegal
Yale University Press. New Haven and London. 400 pgs.
(ISBN: 0-300-07454-9)

Biaggi, Virgilio. 1970.
Las Aves de Puerto Rico
Editorial Universitaria. Universidad de Puerto Rico. 371 pgs. (Spanish)

Brown, Leslie H, Emil K. Urban and Kenneth Newman. 1982.
The Birds of Africa. Volume I.
Academic Press. London - New York. 521 pgs.
(ISBN: 0-12-137301-0)

Clancey, P. A. 1964.
The Birds of Natal and Zululand
Oliver & Boyd. Edinburgh and London. 511 pgs.

Clements, James F. 2000.
Birds of the World: A Checklist: Fifth Edition.
Ibis Publishing Company. Vista, California. 867 pgs.
(ISBN: 0-934797-16-1)

Cramp, Stanley, et all. 1977.
Handbook of the birds of Europe, the Middle East, and North Africa: the birds of the Western Palearctic. Volume 1: Ostrich - Ducks
Oxford University Press. Oxford, London and New York. 722 pgs.
(ISBN: 0-19-857358-8)

del Hoyo, Josep, Andrew Elliott and Jordi Sargatal. 1992.
Handbook of the birds of the world: Vol. 1. Ostrich to Ducks
Lynx Edicions. Barcelona. Pgs 376-417.
(ISBN: 84-87334-10-5)

Edwards, Ernest Preston. 1998.
A field guide to the birds of Mexico and adjacent areas: Beliza, Guatemala, and El Salvador
University of Texas Press. Austin. 209 pgs.
(ISBN 0-292-72092-0 and 0-292-72091-2)

Goodall, J. D., A. W. Johnson and Dr. R. A. Philippi B. 1951.
Las Aves de Chile: su conocimiento y sus costumbres: Tomo Segundo
Platt Establecimuentos Gráficos S. A. 445 pgs. (Spanish)

Gyldenstolpe, Nils. 1945.
A ConTribetion to the Ornithology of Northern Bolivia.
Almqvist & Wiksells Boktryckeri AB. Stockholm. 301 pgs.

Hanzak, J. 1972.
Gran Enciclopedia Ilustrada de las Aves
Traducción de Elizabeth Eckstein E. Revisión de J. Racenis. Círculo de Lectores.
Lectura. Caracas, Venezuela. 582 pgs. (Spanish)

Haverschmidt, F. 1968.
Birds of Surinam
Oliver & Boyd. Edinburgh and London. 445 pgs.

Henry, G. M. 1971.
A Guide to the Birds of Ceylon
Oxford University Press. London, New York, Bombay.

Howard, Richard and Alick Moore. 1991.
A complete checklist of the birds of the world. Second Edition.
Academic Press. San Diego, California. Pgs 13-15.
(ISBN 0-12-356910-9)

Langrand, Oliver. 1990.
Birds of Madagascar
Yale University Press. New Haven & London. 364 pgs.
(ISBN: 0-300-04310-4)

MacKinnon, John and Karen Phillipps. 1993.
A Field Guide to the Birds of Borneo, Sumatra, Java and Bali
Oxford University Press. Oxford, New York, Tokyo. 491 pgs.
(ISBN: 0 19 854035 3)

Narosky, T. and D. Yzurieta. 1989.
Guía para la identificación de las aves de Argentina y Uruguay
Vazquez Mazzini Editores. Buenos Aires, Argentina. 346 pgs.
(ISBN 950-99063-0-1) (Spanish)

Olrog, Claës Chr. 1968.
Las Aves Sudamericanas: Una guía de campo
Tomo Primero (Pingüinos - Pájaros Carpinteros)
Universidad Nacional de Tucumán. Fundación - Instituto “Miguel Lillo”. Argentina. 505 pgs. (Spanish)

Pizzey, Graham. 1980.
A field guide to the Birds of Australia
Princeton University Press. Princeton, New Jersey. 460 pgs.
(ISBN 0-691-08277-4)

Pratt, H. Douglas, Phillip L. Bruner, and Delwyn G. Berrett. 1987.
A field guide to the birds of Hawaii and the Tropical Pacific
Hawaii Audubon Society. Princeton University Press. Princeton, New Jersey. Pgs 90-91.
(ISBN 0-691-08402-5 and 0-691-02399-9)

Rodríguez, José Vicente. 1982.
Aves del Parque Nacional Natural los Katíos: Antioquia, Chocó, Colombia
Proyecto ICA. Talleres Inderena. Bogota. 328 pgs. (Spanish)

Sheldon, Frederick H. 1987.
Phylogeny of Herons Estimated from DNA-DNA Hybridization Data
The Auk. Vol 104. Pgs 97-108.

Shirihai, Hadoram. 1996.
The Birds of Israel
Academic Press Limited. London. 692 pgs.
(ISBN 0-12-640255-8)

Sibley, Charles G. and Burt L. Monroe, Jr. 1990.
DisTribetion and Taxonomy of Birds of the world.
Yale University Press. New Haven and London. Pgs 302-306.
(ISBN 0-300-04969-2)

Sinclair, Ian, Phil Hockey and Warwick Tarboton. 1993.
Ilustrated Guide to the Birds of Southern Africa
Princeton University Press. Princeton, New Jersey. 426 pgs.
(ISBN: 0 691 04469 4)

Smythies, Bertram E. 1968.
The birds of Borneo
Oliver & Boyd. Edinburgh and London. 593 pgs.

Voisin, Claire. 1991.
The Herons of Europe
T & A D Poyser. London. 364 pgs. (ISBN: 0 85661 063 1)

Zimmerman, Dale A., Donald A. Turner and David J. Pearson. 1996.
Birds of Kenya and Northern Tanzania
Princeton University Press. Princeton, New Jersey. 740 pgs.
(ISBN: 0-691-02658-0)