Choldin, Harvey M.
McGraw-Hill, 1985
Buku Teks
edited by Julian Custer
Clanrye International, 2018
Buku Teks
Mercer, Charles, author
Penguin Books, 1975
Buku Teks
edited by Jo Little, Linda Peake, and Pat Richardson
Macmillan, 1988
Buku Teks
Parfect, Michael, author
Routledge, 1997
Buku Teks