Dubin, Fraida
Cambridge University Press, 1986
Buku Teks
edited by Bernhard Kettemann and Robert N. St. Clair
Gunter Narr Verlag Tubingen, 1980
Buku Teks SO
Wallace, Michael J.
Cambridge University Press, 2004
Buku Teks
Tsui, Amy B. M.
Cambridge University Press, 2003
Buku Teks
Ur, Penny
Cambridge University Press, 2006
Buku Teks