Klein, Mitchell S.G., author
Prentice-Hall, 1984
Buku Teks
Koopmans, Tim, author
Cambridge University Press, 2003
Buku Teks
edited by Christopher J. Whelan
Clarendon Press, 1990
Buku Teks
Christian Soe
McGraw-Hill, 2004
Buku Teks
Macridis, Roy C., author
Dorsey Press, 1972
Buku Teks