1. Lake Ngami or Explorations and Discovery during Four Years Wanderings in the Wilds of South Western Africa.;Andersson,1857
2. The problem of imitation;Aronfreed,1969
3. A note on the behavior of the chimpanzee;Beatty;J. Mammal.,1951
4. The relation of previous experience to insightful problem-solving;Birch;J. Comp. Psychol.,1945