Waddington, C.H., author
ST. Martin Press, 1978
Buku Teks
edited by Nigel Cross, David Elliott and Robin Roy
Hutchinson Educational , 1974
Buku Teks
Saaty, Thomas L., author
Praeger, 1990
Buku Teks
Crowe, Norman, author
MIT Press, 1995
Buku Teks
Ackoff, Russell Lincoln, 1919-, author
John Wiley & Sons, 1974
Buku Teks