1. Hoatzin nestling locomotion: Acquisition of quadrupedal limb coordination in birds
2. Adams, C. (1913).Guide to the study of animal ecology. New York, NY: Macmillan Company.
3. Ames, E. (2008).Carl Hagenbeck's empire of entertainments. Seattle, WA: University of Washington Press.
4. Annual reports of the New York Zoological Society. (1897). New York, NY: NYZS.
5. Baatz, S. (1990).Knowledge, culture, and science in the metropolis: The New York Academy of Sciences, 1817–1970. New York, NY: New York Academy of Sciences.