TY  - RPRT
TI  - Inducing a preference for morphine in rats without premedication.
AU  - R Kumar
AU  - H Steinberg
AU  - I P Stolerman
PY  - 1968
DO  - 10.1038/218564a0
UR  - https://pubmed.ncbi.nlm.nih.gov/5689915/
ID  - 5689915
ER  -