Scott, Austin Wakeman, 1884-1981, author
Little, Brown, 1963
Buku Teks
Donaldson, Thomas
Prentice-Hall, 1981
Buku Teks
Henn, Harry, Alexander, John R
St.Paul,Minn : West publishing Co, 1983,
Buku Referensi
Gardner, Simon
Clarendon Press, 1990
Buku Teks
Ramjohn, Mohamed
Cavendisch Publishing, 1998
Buku Teks