Longman, 1979
Buku Teks
University of Notre Dame Press, 1979
Buku Teks
Wesson, Robert G
Houghton mifflin, 1977
Buku Teks
Thompson, Kenneth W., author
Lousiana State University Press, 1980
Buku Teks
edited by Stephen Clarkson
The Canadian, 1968
Buku Teks