San Diego : Sosiological Abstracts Inc.
Majalah, Jurnal, Buletin
edited by Albert H. Marckwardt
National Council of Teachers of English, 1968
Buku Teks
Hannan, E.J., author
John Wiley, 1970
Buku Teks
edited by David F. Findley
Academic Press, 1978
Buku Teks
Fuller, Wayne A., author
John Wiley & Sons, 1976
Buku Teks