Willey, Joanne M., author
Mc Graw Hill, 2008
Buku Teks
Beal, George M.
Iowa State University Press , 1962
Buku Teks
Barban, Arnold N.
NTC Business Books, 1993
Buku Teks
Hamilton, Mark, author
Neo-tech books, 2000
Buku Teks
Delhaye, J.M.
McGraw-Hill, 1980
Buku Teks