1. Stedman's medical dictionary,2016
2. The Free Radical Theory of Aging;Harman;Antioxid Redox Signal,2003
3. The illegal parrot trade: a literature review;Pires;Glob Crime,2012
4. Chapter 15: Quality-of-life assessment and end-of-life planning for geriatric zoo animals;Vogelnest,2019
5. Evolution and the biology of aging;Cohen,2014