Amstrong, David F., author
Cambridge University Press, 1995
Buku Teks
edited by David McNeill
Cambridge University Press, 2000
eBooks
Goldberg, Adele E., author
Oxford Univertity Press, 2006
Buku Teks
edited by Eleni Efthimiou, Georgios Kouroupetroglou, Stavroula-Evita Fotinea
Springer-Verlag, 2012
eBooks
Williams, Marta, author
New World Library, 2003
Buku Teks