Ur, Penny, author
Cambridge University Press, 2006
Buku Teks
Rivers, Wilga M., author
Cambridge University Press, 1994
Buku Teks
Luzi Adriyanti, author
Universitas Indonesia, 2004
UI - Tesis (Membership)
Springer, 2016
Buku Teks
Kittson, E. Creagh
Milford, 1926
Buku Teks