1. Allegheny County, Department of Planning and Development (1976). ?Pittsburgh CBD Cordon Study,? September 1976.
2. Bata, A. F. (1974). ?The Effects of the 1972 Trenton, New Jersey, Bus Strike on the Modal Choice of the Commuters,? MA Thesis, Northwestern University, Evanston, Urban Mass Transportation Administration.
3. Urban Systems Institute of Carnegie-Mellon University (1975). ?An Evaluation of the Carpool-Public Transit Program,? Report to the Southwestern Pennsylvania Regional Planning Commission.
4. Voorhees, A. M. and Associates, Inc. (1974). ?Guidelines to Reduce Energy Consumption Through Transportation Actions.?
5. Wegmann, F. J. et al. (1979). ?Impact of the 1977 Transit Strike in Knoxville,? TRB Research Record No. 719, Transit Development.