Bent, Arthur Cleveland. 1940. Life Histories of North American Cuckoos, Goatsuckers, Hummingbirds, and their Allies (Orders Psittaciformes, Cuculiformes, Trogoniformes, Coraciiformes, Caprimulgiformes, and Micropodiiformes). Smithsonian Institution Bulletin 176. Washingon, DC: U.S. National Museum.