1. Guidelines for Perinatal Care;ACOG,1988
2. Nurse-midwifery in the United States 1982;Adams,1984
3. Pesquisa Nacional Sobre Saude Materno-infantil e Planejamento Familiar, Brasil 1986;Arruda,1987
4. Enquête Nationale sur la Plantification Familiale, la Fécondité et la Santé de la Population au Maroc, 1987;Azelmat,1989
5. Antenatal care in the countries of the European Community over the last twenty years;Blondel,1986