Virutamasen, P., Reinprayoon, D., Wongwathanavikrom, R., Nitichai , Y., Nilakarn, T. and Poomsuwan, P. 1989. Clinical and Metabolic Study of Triphasic Contraceptive Pill (Triquilar)® . Thai Journal of Obstetrics and Gynaecology. 1, 1 (Jan. 1989), 31–38.