Costa, Aleksandra Pereira, Leila Alcina Correia Vaz Bustorff, Ana Rita Ribeiro da Cunha, Maria Cidney da Silva Soares, and Verbena Santos Araújo. 2011. “Contributions of Prenatal Care for the Vaginal Childbirth: Mothers’ Perception”. Rev Rene 12 (3). http://www.periodicos.ufc.br/rene/article/view/4283.