Scott, W. Richard, 1932-, author
Holt,Rinehart and winston, 1970
Buku Teks
Hall, Richard H., author
Prentice-Hall, 2002
Buku Teks
Smith, Anthony D., author
Longman, 1976
Buku Teks
Smith, Anthony D., author
Longman, 1976
Buku Teks
Bartholomew, David J., author
John Wiley & Sons, 1982
Buku Teks