Oxford Univesity Press, 1994
Buku Referensi
Oxford University press , 1994
Buku Teks
edited by Colin Howlett
Oxford University Press, 1996
Buku Referensi
edited by P. S. Falla
Clarendon Press, 1990
Buku Referensi
edited by Judy Pearsall, Bill Trumble
Oxford University Press, 1995
Buku Referensi