George Allen and Unwin, 1963
Buku Teks
Kautsky, John H., author
John Wiley & Sons, 1967
Buku Teks
Wibbels, Erik, author
Cambridge University Press, 2005
Buku Teks
Staley, Eugene, author
Published for the Council on Foreign Relations by Harper, 1961
Buku Teks
Beeby, C. E., author
Harvard University Press, 1966
Buku Teks