Molineu, Harold
Westview Press, 1990
Buku Teks SO
Hayes, Margaret Daly
Westview Press, 1984
Buku Teks SO
Hirschman, Albert O.
Twentieth Century Fund, 1963
Buku Teks
Teichert, Pedro C.M.
Bureau of Business Research Mississippi University , 1959
Buku Teks
Szulc, Tad
Atheneum, 1966
Buku Teks SO