PORRAS MACÍAS, Agustín. Gerald I. Zatuchni, Comp., Post-partum Family Planning, Nueva York, McGraw-Hill Book Company, 1970, 477 p. Estudios Demográficos y Urbanos, [S. l.], v. 6, n. 02, p. 271–272, 1972. DOI: 10.24201/edu.v6i02.184. Disponível em: https://estudiosdemograficosyurbanos.colmex.mx/index.php/edu/article/view/184. Acesso em: 30 abr. 2025.