Keeble, Richard, author
Routledge , 2009
Buku Teks
Keeble, Richard, author
Routledge, 2001
Buku Teks
Wina Armada Sukardi, author
Dewan Pers, 2007
Buku Teks
Bart Streumer.
Wiley-Blackwell , 2014
Buku Teks
Kagan, Shelly, author
Westview Press, 1997
Buku Teks