Jimenez L., Luis Felipe
United Nations, Economic Commission for Latin America and the Carbbean, 1998
Buku Teks
Cline, William R., author
Praeger, 1972
Buku Teks
Gordon, Lincoln, author
Harvard University Press, 1963
Buku Teks
edited by Egbert De Vries, Jose Medina Echavarria
UNESCO, 1967
Buku Teks
edited by Werner Baer and Isaac Kerstenetzky
Richard D. Irwin, 1964
Buku Teks