O`Shaughnessy, Douglas, 1950-, author
Addison-Wesley, 1987
Buku Teks
Byrd, Dani, author
Wiley-Blackwell, 2010
Buku Teks
Hybels, Saundra, author
D. Van Nostrand, 1974
Buku Teks
Bormann, Ernest G., author
Harper & Row, 1965
Buku Teks
Ellingsworth, Huber W., author
Prentice-Hall, 1967
Buku Teks