@article{article04899444,
title   = {Molecular mechanism of action of peripheral morphine analgesia: stimulation of the cgmp system via nitric oxide release},
author = {Ferreira, S. H. and Duarte, I D G and Lorenzetti, B B},
year = {1991},
doi = {10.1016/0014-2999(91)90333-l},
journal   = {Journal of Pharmacology}
}