1. See, Julius Isaac,Economics of Migration. New York: Oxford University Press, 1947, p. 62.
2. Gino Germani, “Inquiry into the Social Effects of Urbanization in a Working-class Sector of Greater Buenos Aires”. In Philip Hauser (ed.),Urbanization in Latin America. Paris: UNESCO, 1961.
3. José Luis Romero,Las ideas politicas en Argentina. Mexico: Fondo de Cultura Económica, 1956, p. 176; and Domingo F. Sarmiento,Condición del Extranjero en América. Buenos Aires: A. B. Sarmiento, 1900,Obras Completas, Volume V, pp. xxxvi and p. 73 andpassim.
4. Julius Isaac,op. cit., chap. VI.
5. Joseph J. Spengler, “Effects Produced in Receiving Countries by Pre-1939 Immigration”. In Brinley Thomas (ed.),Economics of International Migration. London: Macmillan, 1958, p. 22 ff.