Evans, John S.
Dryden Press , 1992
Buku Teks
Baker, James C., author
Prentice-Hall, 1998
Buku Teks
Baily, Martin Neil, author
Richard D. Irwin, 1995
Buku Teks
Cambridge University Press, 1995
Buku Teks
Honeygold, Derek
Woodhead-Faukner , 1989
Buku Teks