Bloomsbury, 1990
Buku Referensi
Sharpe, Gareth
Guinness Publishing, 1994
Buku Referensi
consultant ed. Tanya A. McFerran
Oxford University Press, 1996
Buku Referensi
Cohen, J.M. (John Michael), 1903-1989
Viking, 1993
Buku Referensi
Paxton, John
J.M. Dent & Sons, 1992
Buku Referensi