@book{bhlitem21332, title = {Chicago winter birds }, volume = {no.2 (1922)}, copyright = {Public domain. The BHL considers that this work is no longer under copyright protection.}, url = {https://www.biodiversitylibrary.org/item/21332}, note = {https://www.biodiversitylibrary.org/bibliography/3272}, publisher = {Chicago, Field Museum of Natural History, 1922}, author = {Sanborn, Colin Campbell,}, year = {1922}, pages = {20}, keywords = {Birds|Chicago|Illinois}, }