Finch, Deborah M. 1991. Population Ecology, Habitat Requirements, and Conservation of Neotropical Migratory Birds. General Technical Report, RM-205. Fort Collins, CO: USDA Forest Service, Rocky Mountain Forest and Range Experiment Station. https://www.fws.gov/southwest/es/documents/R2ES/LitCited/LPC_2012/Finch_1991.pdf