Trautman, Neal E., author
Pearson Prentice Hall, 2005
Buku Teks
Smart, Huw, author
Oxford University Press, 2006
Buku Referensi
Reiss, Albert J.
Yale University Press, 1971
Buku Teks
Bunyard, R.S.
London McGraw-Hill c. 1979,
Buku Teks
Wilkie, Roy
Harvester Press, 1986
Buku Teks