Brewer, E. Cobham
New York, Harper Brothers
Buku Referensi
revised by Ivor H. Evans
Cassell & Company, 1975
Buku Referensi
Comfort, Nicholas
Cassell Publishers, 1993
Buku Referensi
Cassell, 1993
Buku Referensi
Donald, Graeme
Simon & Schuster, 1994
Buku Referensi