A protocol to identify non-classical risk factors for preterm births: the brazilian Ribeirão Preto and São Luís prenatal cohort (BRISA) - Silva, Antonio Augusto Moura da; Simões, Vanda Maria Ferreira; Barbieri, Marco Antonio; Cardoso, Viviane Cunha; Alves, Claudia Maria Coelho; Thomaz, Erika Bárbara Abreu; Queiroz, Rejane Christine de Sousa; Cavalli, Ricardo de Carvalho; Batista, Rosângela Fernandes Lucena; Bettiol, Heloisa (Reproductive Health, 2014)