Sandler, Wendy, author
Cambridge University Press, 2006
Buku Teks
Stokoe, William C., author
Mouton, 1972
Buku Teks
Morgan Kaufmann, 2013
eBooks
Horton, William, author
ASTD Press, 2001
Buku Teks
Lee, Alfred McClung
Rinehart & Company, 1953
Buku Teks