Smith, L. Glenn
Allyn and Bacon, 1973
Buku Teks
Ewen, Dale
Prentice-Hall, 1983
Buku Teks
Gila Hanna
Springer, 2012
eBooks
edited by Lyn D. English ; associate editors, Maria Bartolini Bussi ... [and others]
Routledge, 2008
Buku Teks SO
Tokyo ISEI 1990,
Buku Teks