Allen, S. J., Bejder, L., & Krόtzen, M. (2011). Why do Indo-Pacific bottlenose dolphins (Tursiops sp.) carry conch shells (Turbinella sp.) in Shark Bay, Western Australia? Marine Mammal Science, 27(2), 449–454.

Auersperg, A. M., Von Bayern, A. M., Gajdon, G. K., Huber, L., & Kacelnik, A. (2011). Flexibility in problem solving and tool use of kea and New Caledonian crows in a multi access box paradigm. PLoS ONE, 6(6), e20231.

Bird, C. D., & Emery, N. J. (2009). Rooks use stones to raise the water level to reach a floating worm. Current Biology, 19(16), 1410–1414.

Biro, D., Inoue-Nakamura, N., Tonooka, R., Yamakoshi, G., Sousa, C., & Matsuzawa, T. (2003). Cultural innovation and transmission of tool use in wild chimpanzees: Evidence from field experiments. Animal Cognition, 6(4), 213–223.

Bluff, L. A., Weir, A. A., Rutz, C., Wimpenny, J. H., & Kacelnik, A. (2007). Tool-related cognition in New Caledonian crows. Comparative Cognition & Behavior Reviews, 2, 1–25.

Cheke, L. G., Bird, C. D., & Clayton, N. S. (2011). Tool-use and instrumental learning in the Eurasian jay (Garrulus glandarius). Animal Cognition, 14(3), 441–455.

Deecke, V. B. (2012). Tool-use in the brown bear (Ursus arctos). Animal Cognition, 15(4), 725–730.

Dinets, V., Brueggen, J. C., & Brueggen, J. D. (2015). Crocodilians use tools for hunting. Ethology Ecology & Evolution, 27(1), 74–78.

Emery, N. J., & Clayton, N. S. (2009). Tool use and physical cognition in birds and mammals. Current Opinion in Neurobiology, 19(1), 27–33.

Finn, J. K., Tregenza, T., & Norman, M. D. (2009). Defensive tool use in a coconut-carrying octopus. Current Biology, 19(23), R1069–R1070.

Fox, E. A., Sitompul, A. F., & van Schaik, C. P. (1999). Intelligent tool use in wild Sumatran orangutans. In S. T. Parker, R. W. Mitchell, & H. L. Miles (Eds.), The Mentalities of Gorillas and Orangutans: Comparative Perspectives (pp. 99–116). Cambridge: Cambridge University Press.

Gumert, M. D., Hoong, L. K., & Malaivijitnond, S. (2011). Sex differences in the stone tool-use behavior of a wild population of burmese long-tailed macaques (Macaca fascicularis aurea). American Journal of Primatology, 73(12), 1239–1249.

Hall, K. R. L., & Schaller, G. B. (1964). Tool-using behavior of the California sea otter. Journal of Mammalogy, 45(2), 287–298.

Hart, B. L., Hart, L. A., McCoy, M., & Sarath, C. R. (2001). Cognitive behaviour in Asian elephants: Use and modification of branches for fly switching. Animal Behaviour, 62(5), 839–847.

Kacelnik, A. (2009). Tools for thought or thoughts for tools? Proceedings of the National Academy of Sciences, 106(25), 10071–10072.

Krόtzen, M., Mann, J., Heithaus, M. R., Connor, R. C., Bejder, L., & Sherwin, W. B. (2005). Cultural transmission of tool use in bottlenose dolphins. Proceedings of the National Academy of Sciences of the United States of America, 102(25), 8939–8943.

Rutz, C., & St Clair, J. J. (2012). The evolutionary origins and ecological context of tool use in New Caledonian crows. Behavioural Processes, 89(2), 153–165.

Suzuki, S., Kuroda, S., & Nishihara, T. (1995). Tool-set for termite-fishing by chimpanzees in the Ndoki Forest, Congo. Behaviour, 132(3), 219–235.

Taylor, A. H., Knaebe, B., & Gray, R. D. (2012). An end to insight? New Caledonian crows can spontaneously solve problems without planning their actions. Proceedings of the Royal Society of London B: Biological Sciences, 279(1749), 4977-4981.

Tebbich, S., Taborsky, M., Fessl, B., & Blomqvist, D. (2001). Do woodpecker finches acquire tool-use by social learning? Proceedings of the Royal Society of London B: Biological Sciences, 268(1482), 2189–2193.

Tinbergen, N. (1963). On aims and methods of ethology. Zeitschrift Fόr Tierpsychologie, 20(4), 410–433.

Visalberghi, E., & Limongelli, L. (1994). Lack of comprehension of cause-effect relations in tool-using capuchin monkeys (Cebus apella). Journal of Comparative Psychology, 108(1), 15-22.

Wynne, C. D., & Udell, M. A. (2013). Reasoning. In Animal Cognition: Evolution, Behavior and Cognition (pp. 117-139). Palgrave Macmillan.