Rayner, William, author
Frederick A. Praeger, 1962
Buku Teks
Yudelman, Montague, author
Harvard University Press , 1975
Buku Teks
edited by Virginia Gamba-Stonehouse
Institute for Security Studies, 2000
Buku Teks
Parrinder, Geoffrey
Hutchinson's University Library, 1954
Buku Teks
Booth, Alan R., author
Westview Press, 1983
Buku Teks