TY  - RPRT
TI  - Factors affecting voluntary morphine intake in self-maintained addicted rats.
AU  - J R Weeks
AU  - R J Collins
PY  - 1964
DO  - 10.1007/bf00413156
UR  - https://pubmed.ncbi.nlm.nih.gov/5890552/
ID  - 5890552
ER  -