website: AOU Check-List (08-2011); American Ornithologists' Union's "Check-list of North American Birds - List of the 2,078 Bird Species Known From the A.O.U. Check-list Area" (AOU Check-list, 7th edition, updated with Supplements 42-52), maintained at http://www.aou.org/
website: Zoonomen - Zoological Nomenclature Resource, 2011.02.25; "Zoonomen - Zoological Nomenclature Resource" maintained by Alan P. Peterson at http://www.zoonomen.net
website: AOU Check-List (07-2005); American Ornithologists' Union's "LIST OF THE 2,037 BIRD SPECIES (WITH SCIENTIFIC AND ENGLISH NAMES) KNOWN FROM THE A.O.U. CHECK-LIST AREA" (AOU Check-list, 7th edition, updated with Supplements 42-46), maintained at http://www.aou.org/
website: IOC World Bird List, Master List v2.9; Master list and sub-lists are maintained at http://www.worldbirdnames.org/names.html, and 'virtually replace' Gill & Wright 2006 (Birds of the World, Recommended English Names)
Gill, Frank, and Minturn Wright 2006-01-01. Birds of the World: Recommended English Names. Princeton University Press. Princeton, New Jersey, USA. ix + 259. 0-691-12827-8. Includes a CD-ROM with the full dataset.