1. ILLPO, A.—"New classification and nomenclature for Newborn Infants including Prematures and Abortions". The Proceedings of the Eighth Northern Pediatric Congress 1946, in Helsinski, Finland; Acta Paediat. 1947.
2. A. M. A.—"Standard Nomenclature of Diseases and Operations".
3. BUNDESEN H. N.—"Natal Day Deaths. The Long-neglected field of Infant Mortality". J. A. M. A. 153: 466, oct. 3 de 1953.
4. OBES POLLERI.—"Prematuro". P. 36. Ed. García Morales. Montevideo, Uruguay. 1952.
5. HAMMOND, J.—"Physiological factors affecting birth weight". Proceeding of the Nutrition Society; 2: 8. 1944.