Koontz, Harold, author
Binakawan Study Club, 1969
Buku Teks
Rejda, George E.
Pearson Addison Wesley , 2008
Buku Teks
Hodges, Henry G., author
Houghton Miffiln, 1955
Buku Teks
by Arthur J. Keown, John D. Martin, J. William Petty, David F. Scott
Prentice-Hall, 2001
Buku Teks
Jeynes, Jacqueline, author
Butterworth-Heinemann, 2002
Buku Teks