edited by Michael H. Whitworth
Blackwell, 2007
Buku Teks
Trulove, James Grayson
HarperCollins, 2001
Buku Referensi
Holt, Rinehart and Winston,, 1977
Buku Teks
Len Platt
Cambridge University Press, 2011
eBooks
edited and introduced by Peter Brooker
Longman, 1992
Buku Teks