Witting, Amy
Penguin Books, 1990
Buku Teks
Degenova, Mary Kay, author
McGraw-Hill , 2008
Buku Teks
Olson, David H., author
McGraw-Hill , 2006
Buku Teks
Lamanna, Mary Ann, author
Wadsworth and Cengage Learning, 2011
Buku Teks
Williams, Brian K., author
Pearson Education, 2006
Buku Teks