Uncle Dave's Reptile Page,
https://www.researchgate.net/publication/271994159_Crocodilians_use_tools_for_hunting
https://www.researchgate.net/publication/271994159_Crocodilians_use_tools_for_hunting
(2015). Crocodilians use tools for hunting. Ethology Ecology
The scientific article which describes the behaviour can be found here: http://www.tandfonline.com/doi/abs/10.1080/03949370.2013…
University of Tennessee, 2013 study