@book{bhlitem260083, title = {Species taxa of North American birds; a contribution to comparative systematics }, copyright = {In copyright. Digitized with the permission of the rights holder.}, url = {https://www.biodiversitylibrary.org/item/260083}, note = {https://www.biodiversitylibrary.org/bibliography/155019}, publisher = {Cambridge, Mass, The Club, 1970}, author = {Mayr, Ernst, and Short, Lester L. and Short, Lester L.}, year = {1970}, pages = {144}, keywords = {Birds|Classification|North America|Species|}, }