by Amilcar O. Herrera ... [et al.]
International Development Research Centre, 1976
Buku Teks SO
edited by Heraldo Munoz and Joseph S. Tulchin
Westview Press, 1984
Buku Teks SO
David B. Guralnik, editor in chief
William Collins Publishers, 1976
Buku Referensi
David B. Guralnik, editor in chief
Prentice-Hall, 1986
Buku Referensi
Victoria Neufeldt, David B. Guralnik, editor
Webster's New World, 1988
Buku Referensi