1. U.S. Department of Transportation, Office of Environment and Urban Systems,Metropolitan Transportation Planning Seminars, December 1971.
2. Smith, Richard Warren, ?Transportation and Urban Form,? M. Arch. Thesis, M.I.T., 1966.
3. Mesarovic, M. D.,The Control Of Multivariable Systems, 1960, p. 14.
4. Vickers, Geoffrey,Freedom In A Rocking Boat, 1970, p. 99.
5. Schutzenberger, M. P., ?A Tentative Classification of Goal Seeking Behaviors,? in F. E. Emery, ed.,Systems Thinking, 1969, p. 211.