Thorelli, H.B., author
Penguin Books, 1973
Buku Teks
Markin, Rom J., author
John Wiley & Sons, 1982
Buku Teks
edited by Edward C. Bursk and John F. Chapman
New American Library, 1964
Buku Teks
Ryan, William
Learning System of Company, 1971
Buku Teks
Lovelock, Christopher H., author
Prentice-Hall, 2005
Buku Teks