Hirst, Francis W.
E.P. Dutton & Co , 1906
Buku Teks
Todd, Paul
London : Balckstone, 1994,
Buku Referensi
Levy, Hermann
Macmillan, 1927
Buku Teks
Scott, Austin Wakeman, 1884-1981
Little, Brown, 1963
Buku Teks
Hudson, Alastair
Cavendish Publishing Limited, 2003
Buku Teks