Pigford, D.V., author
Boston Boyd & Fraser , 1990
Buku Teks
Alty, J.L., author
NCC Publications, 1984
Buku Teks
edited by Barry G. Silverman
Addison-Wesley, 1987
Buku Teks
Harmon, Paul, author
John Wiley & Sons, 1985
Buku Teks SO
Gallagher, John P., author
Prentice-Hall, 1988
Buku Teks