edited by Jessie Ee
McGraw-Hill, 2004
Buku Teks
Ruggiero, Vincent Ryan
McGraw-Hill, 2008
Buku Teks
Donaldson, T.H.
Houndmills, Hampshire Macmillan Press 1988,
Buku Teks
Hotton, Geoffrey
Tavistock Publications in association with Bath University Press, 1972
Buku Teks
edited by Stephen G. Haines
Systems Thinking Press, 2007
Buku Teks