"Summary with links to pdf"@en. "http://www.aou.org/checklist/". . . . "1983". . . "Checklist of North American Birds 7th Edition"@en. . . _:wyyYUkWh834. _:wyyYUkWh833. . . . . . . . . . . . . "Source: Freebase - The World's database". . . "1-891276-00-X"@en. . . . . _:wyyYUkWh834 . _:wyyYUkWh834 "best". _:wyyYUkWh833 . _:wyyYUkWh833 "checklist_of_north_american_birds_7th_edition".