Estevão, R. A. F., A. C. P. Nazário, and E. C. Baracat. “Effect of Oral Contraceptive With and Without Associated Estriol on Ultrasound Measurements of Breast Fibroadenoma: Randomized Clinical Trial”. São Paulo Medical Journal, vol. 125, no. 5, Sept. 2007, pp. 275-80, https://periodicosapm.emnuvens.com.br/spmj/article/view/2160.