Nafziger, E. Wayne
Prentice-Hall, 1990
Buku Teks SO
Angelopoulos, Angelos
Preager, 1972
Buku Teks
Nafziger, E. Wayne
Cambridge University Press, 2006
Buku Teks SO
International Development Cooperation Agency, 1981
Buku Teks SO
by Robert E. Asher ... [and others]
Brookings Institution, 1962
Buku Teks SO