Robinson, Lois
Harper & Row , 1967
Buku Teks
Cook, Vivian, author
ARNOLD, 2001
Buku Teks
The Hankes Foundation, 1992
Multimedia
Saville-Troike, Muriel, 1936-, author
Cambridge University Press , 2006
Buku Teks
edited by Michael H. Long
Cambridge University Press, 2005
Buku Teks