Dutta, Soumitra
McGraw-Hill, 1999
Buku Teks
Litterer, Joseph August, 1926-
John Wiley & Sons, 1973
Buku Teks
Pfifner, John M.
Prentice-Hall, 1960
Buku Teks
Jay M. Shafritz, J. Steven Ott, editor
Harcourt College, 2001
Buku Teks
edited by Jay M. Shafritz, J. Steven Ott
Wadsworth, 2005
Buku Teks