Merriam-Webster, 1998
Buku Referensi
Ellis Cashmore with Michael Banton, James Jennings, Barry Troyna, Pierre L. Van Den Bergdhe
Routledge, 1996
Buku Referensi
Peter Salim, author
Modern English Press, 1991
Buku Referensi
Delair Publishing Company, 1981
Buku Referensi
G & C Merriam Co., 1947
Buku Referensi