Snyder, Richard C., author
Free Press, 1962
Buku Teks
edited by Roy C. Macridis
Prentice-Hall, 1992
Buku Teks
edited by Roy C. Macridis
Prentice-Hall, 1959
Buku Teks
Modelski, George, author
Frederick A. Praeger, 1962
Buku Teks
Cohen, Bernard Cecil, 1926-, author
Princeton University Press, 1957
Buku Teks