edited by P.M.S. Hacker and J. Raz
Clarendon Press, 1988
Buku Teks
edited by Howard Newby
John Wiley & Sons, 1978
Buku Teks
Huseman, Richard C., author
Allyn and Bacon, 1977
Buku Teks
Cummings, L.L., author
Richard D. Irwin, 1980
Buku Teks
edited by Allan Cochrane, Chris Hamnett and Linda McDowell
Harper and Row, 1981
Buku Teks