Tester, Keith
Routledge, 1992
Buku Teks
Rush, Michael, author
Harvester Wheatsheaf, 1992
Buku Teks
Japan Center for International Exchange, 1999
Buku Teks
Keane, John, author
Cambridge University Press, 2005
Buku Teks
Davis, Kingsley, 1908-1997, author
Macmillan, 1949
Buku Teks