TY  - RPRT
TI  - Opioids: first lessons from knockout mice.
AU  - B L Kieffer
PY  - 1999
DO  - 10.1016/s0165-6147(98)01279-6
UR  - https://pubmed.ncbi.nlm.nih.gov/10101958/
ID  - 10101958
ER  -