edited by Vincent Sherry
Cambridge University Press, 2016
Buku Teks
edited by Michael H. Whitworth
Blackwell, 2007
Buku Teks
Holt, Rinehart and Winston,, 1977
Buku Teks
Williams, Louise Blakeney, author
Cambridge University Press, 2009
eBooks
Trulove, James Grayson, author
HarperCollins, 2001
Buku Referensi