Gregory, Robert Henry, author
Chatto and Windus, 1963
Buku Teks
Seeeions, Laura Steibel, author
Prentice-Hall, 1982
Buku Teks
Crawford, F. Robert, author
Prentice-Hall, 1973
Buku Teks
Harris, Martin L., author
Wiley, 1973
Buku Teks
Casady, Mona J. author
South-Western Publishing, 1985
Buku Teks