GranellaFFarinaSMalferrariGManzoniGC. Drug abuse in chronic headache: A clinico - epidemiologic study. Cephalalgia1987; 7(1):15–20.
2.
HannuchSNMZukermanELimaJGCMasurJ.Use and abuse of analgesic and ergotamine drugs in patients attending a headache unit. A study in São Paulo, Brazil. Cephalalgia1987; 7(Suppl):489–90.