Bloomsbury, 1990
Buku Referensi
edited by Angela Partington
Oxford University Press, 1993
Buku Referensi
Eigen, Lewis D.
Macmillan, 1993
Buku Referensi
edited by A. Norman Jeffares and Martin Gray
HarperCollins, 1995
Buku Referensi
Cohen, John Michael, 1903-1989
Penguin Books, 1971
Buku Referensi