Dummer, Geoffrey William Arnold
Pergamon Press, 1983
Buku Teks
Ingpen, Robert
Dragon's World, 1993
Buku Referensi
Oxford University press , 1994
Buku Teks
Jones, David J.
Second Back Row Press, 1981
Buku Teks
Wilkes, G. A. (Gerald Alfred), 1927-
Fortana/Collins, 1980
Buku Referensi