edited by Ilona Burchroth, Chris Parkin
Learning Matters, 2010
Buku Teks
Jane Picford, editor
Cavendish Publishing , 2000
Buku Teks
Orford, Jim, author
John Wiley & Sons, 1992
Buku Teks
Smalley, Ruth Elizabeth, author
Columbia University Press, 1971
Buku Teks
Chichester, Myra, author
W.B. Saunders, 1995
Buku Teks