1. Proceedings of an International Workshop on Intrauterine Contraception, May 29–June 1, 1984,1985
2. RenaerM. (1981).Chronic Pelvic Pain in Women. Springer-Verlag, Berlin, p. 4
3. GoldstuckN. D. (1979). The management of intrauterine device related pain.Br. J. Fam. Plann.,5, 63–65
4. SnyderS. H. (1979). Opiate receptors and internal opiates.Sci. Am.,236(3), 44–56
5. DawoodM. Y. (1985). Dysmenorrhoea.J. Reprod. Med.,30, 154–167