1. Bottjer, S. W., & Arnold, A. P. (1985). Cerebral lateralization in birds. In S. Glick (Ed.), Cerebral lateralization in nonhuman species (pp. 11–38). Orlando: Academic.
2. Brown, R. (1973). A first language: The early stages. Cambridge, MA: Harvard University Press.
3. Colbert-White, E. N., Covington, M. A., & Fragaszy, D. M. (2011). Social context influences the vocalizations of a home-raised African Grey parrot (Psittacus erithacus erithacus). Journal of Comparative Psychology, 125(2), 175.
4. Colbert-White, E. N., Corballis, M. C., & Fragaszy, D. M. (2014). Where apes and songbirds are left behind: A comparative assessment of the requisites for speech. Comparative Cognition & Behaviour Reviews, 9, 98.
5. Cussen, V. A. (2017). Psittacine cognition: Individual differences and sources of variation. Behavioural Processes, 134, 103–109.