TY  - RPRT
TI  - A method for the objective study of tool-using behavior.
AU  - R W Powell
AU  - W Kelly
PY  - 1975
DO  - 10.1901/jeab.1975.24-249
UR  - https://pubmed.ncbi.nlm.nih.gov/16811876/
ID  - 16811876
ER  -