Gillman MA, Lichtigfeld FJ (1981). „A comparison of the effects of morphine sulphate and nitrous oxide analgesia on chronic pain states in man”. J. Neurol. Sci. 49 (1): 41—5. PMID7205318. doi:10.1016/0022-510X(81)90186-6.
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Gillman MA, Lichtigfeld FJ (1981). „A comparison of the effects of morphine sulphate and nitrous oxide analgesia on chronic pain states in man”. J. Neurol. Sci. 49 (1): 41—5. PMID7205318. doi:10.1016/0022-510X(81)90186-6.
Gillman MA, Lichtigfeld FJ (1981). „The similarity of the action of nitrous oxide and morphine”. Pain. 10 (1): 110. PMID7232008.