Não informado. (1975). British Journal of Obstetrics and Gynaecology. Royal College of Obstetricians and Gynaecologists.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. British Journal of Obstetrics and Gynaecology. London: Royal College of Obstetricians and Gynaecologists, 1975.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. British Journal of Obstetrics and Gynaecology. Royal College of Obstetricians and Gynaecologists, 1975.
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