Murray, John, author
Routledge , 1999
Buku Teks
Azar, Betty Schrampfer, 1941-, author
Prentice Hall Regents, 1989
Buku Referensi
Azar, Betty Schrampfer, 1941-, author
Longman, 2002
Buku Teks
Azar, Betty Schrampfer, 1941-, author
Pearson Education, 2009
Buku Teks
Anderson, W.M. (Wendy M.), author
Wiley Publishing Australia Pty Ltd, 2013
Buku Teks