Williams, E.N., author
Allen Lane, 1980
Buku Referensi
Palmer, Alan, author
Penguin Books, 1981
Buku Referensi
Palmer, Alan, author
Penguin Books , 1987
Buku Referensi
edited by David Nelson
Penguin Books, 2003
Buku Referensi
Mautner, Thomas, author
Penguin Book, 2005
Buku Referensi