Woodham, Jonatham M.
Oxford University Press, 1997
Buku Teks
edited by Jack A. Goldstone, Ted Robert Gurr, Farrokh Moshiri
Westview Press, 1991
Buku Teks
Black, C.E.
Alfred A. Knopf, 1961
Buku Teks
Kohn, Hans
D. Van Nostrand, 1965
Buku Teks
Urwick, Lyndall F.
Pitman Publishing Corporation , 1958
Buku Teks