1. The whisperings within;Barash,1979
2. A search for mirror-image reinforcement and self-recognition in the baboon;Benhar,1975
3. Discrimination learning of mirrored cues by rhesus monkeys;Brown;Journal of Genetic Psychology,1965
4. Psychology - Man in perspective;Buss,1973
5. Human nature and the social order;Cooley,1912