«Between 1950 and 1975 the Portuguese infant mortality rate decresed from 94 per thousand to 39 per thousand at an annual rate of 1.8 per cent during the period of 1950-1959, of 2.9 per cent during the following decade, and of 5.8 per cent between 1970 and 1975. (...)»
Instituto Nacional de Estatística - A mortalidade infantil em Portugal : 1950-1975. Lisboa : Imprensa Nacional, 1977 (Série Estudos ; 52). Available at www: <url:https://www.ine.pt/xurl/pub/265129700>.