Christian Soe
McGraw-Hill, 2004
Buku Teks
Barringron, Lowell
Wadsworth and Cengage Learning, 2013
Buku Teks
Le Roy, Michael K.
Thomson Wadsworth, 2007
Buku Teks
Wang, James C.F.
Prentice-Hall, 1994
Buku Teks
edited by Roy C. Macridis, Bernard E. Brown
Dorsey Press, 1968
Buku Teks