Calvani, Terry
Little, Brown, 1988
Buku Teks
edited by Werner Sichel
Ann Arbor, 1970
Buku Teks SO
Posner, Richard A.
The University of Chicago, 1976
Buku Teks SO
Denoon, David B.H.
Council on Foreign Relations Press , 1993
Buku Teks SO
edited by Theodore P. Kovaleff
M.E. Sharpe, 1994
Buku Teks