Bailey, Alfred M. 1894- Pictorial checklist of Colorado birds; : with brief notes on the status of each species in neighboring States of Nebraska, Kansas, New Mexico, Utah, and Wyoming, [electronic resource] / by Alfred M. Bailey and Robert J. Niedrach.. — [Denver] : Denver Museum of Natural History,, 1967.. — 168 p., illus., map (on lining paper), : 124 col. plates. 32 cm.
A condensation of the authors' Birds of Colorado, published in 1965.