TY  - RPRT
TI  - A comparison of responding maintained under second-order schedules of intramuscular cocaine injection or food presentation in squirrel monkeys.
AU  - J L Katz
PY  - 1979
DO  - 10.1901/jeab.1979.32-419
UR  - https://pubmed.ncbi.nlm.nih.gov/117071/
ID  - 117071
ER  -