Oxford University
London, Oxford University Press
Buku Referensi
London, Oxford University Press
Buku Referensi
edited by A. Norman Jeffares and Martin Gray
HarperCollins, 1995
Buku Referensi
Sharpe, Gareth
Guinness Publishing, 1994
Buku Referensi
edited by J.K. Moorhead and Charles Lee
J.M. Dent and Sons, 1932
Buku Referensi