Arber, Edward Alexander Newell, author
Cambridge University Press, 2014
Buku Teks
Spokane, Arnold R.
Prentice-Hall, 1991
Buku Teks
Wasson, Chester R.
Appleton-Century-Crofts, 1968
Buku Teks
Chester, Giraud
Prentice-Hall, 1978
Buku Teks
Arnold, William R.
Houghton Mifflin, 1983
Buku Teks