1. AHVENAINEN E. J.· Asphysia Neonatorum. Ann. Med. Int . Fenniae 42 (supp. 18). 1. 1954.
2. BUDENSEN H. N. and Co. Progress in Reduction of Needless Neonatal deaths. J.A.M.A. 148, 11: 913. March. 1952.
3. GORDON, D. R. and BIRNBAUM . S. J.: " Intrapartum and puerperal infection". Clinical Obstetrics and Gynecology, 2: 693, 1959.
4. International Recomendations on definitions of, live birth and fetal death ( PHS publicationN. 39. National Office of Vital Statistics. Oct. 1950). Manual of the International Statistical Classification of Diseases, Injuries and causes of Death (Sixth revision ; world health organization, 1948), Vol 1: 212.
5. LEE-GREENHILL: Principios y Práctica de Obstetricia . Accidentes del Feto ; 8º Ed. 11 . 1947.