edited by George K. Zollschan and Walter Hirsch
Halsted Press, 1976
Buku Teks
Wallerstein, Immanuel, author
John Wiley , 1966
Buku Teks
Lauer, Robert H., author
Rineka Cipta, 2003
Buku Teks
Halpern, Manfred, author
Princeton University Press, 1963
Buku Teks
Andrain, Charles F., author
Macmillan, 1995
Buku Teks