Modelski, George
Free Press, 1972
Buku Teks
Charles Scribner's , 1970
Buku Teks
Ethridge, Marcus E., author
Wadsworth, 2010
Buku Teks
Friedmann, Wolfgang, 1907-1972, author
W. Van Hoeve, 1954
Buku Teks
Lerner, Max, author
Simon and Schuster , 1962
Buku Teks