Wells, William D., author
Prentice-Hall, 2000
Buku Teks
Moriarty, Sandra E. (Sandra Ernst), author
Prentice Hall International, 1991
Buku Teks
Wells, William D., author
Prentice-Hall, 2000
Buku Teks
Moriarty, Sandra E. (Sandra Ernst), author
Pearson, 2012
Buku Teks
Wells, William D., author
Prentice-Hall, 1988
Buku Teks