Megginson, William L.
McGraw-Hill, 2000
Buku Referensi
Byrd, Mary Jane
mcGraw-Hill , 2000
Multimedia
Timmons, Jeffry A
McGraw-Hill, 204
Buku Teks
Hodgetts, Richard M.
Harcourt College Publishers, 2001
Buku Teks
Hatten, Timothy S.
South Western Cengage Learning, 2012
Buku Teks