1. Adams, D. K. 1929 Experimental studies of adaptive behavior. Comparative Psychology Monographs, 6, 1-168.
2. Adler, H. E. 1955 Some factors of observational learning in cats. Journal of Genetic Psychology, 86, 159-177.
3. Archer, J. 1997 Why do people love their pets? Evolution and Human Behavior, 18, 237-259.
4. The Snark was a Boojum.
5. Berry, C. S. 1908 An experimental study of imitation in cats. The Journal of Comparative Neurology and Psychology, 18, 1-25.