Wilde, William H.
Oxford University Press, 1994
Buku Referensi
Lees, Stella
Oxford University Press, 1993
Buku Referensi
by Peter Dennis, Jeffrey Grey, Ewan Morris, Robin Prior
Oxford University Press, 1995
Buku Referensi
Buku Teks
Saxby, H.M.
Wentworth, 1969
Buku Teks