Williams, Joanna, author
Prafulla, 2005
Buku Teks
Newton, Charles Thomas, author
Cambridge University Press, 2011
eBooks
Hendricks, William O., author
Mouton, 1973
Buku Teks
Smith, Bernard, author
Oxford University Press, 1976
Buku Teks
Armstrong, Kate, author
Michigan State University Press, 2001
Buku Teks