4BLY P H, OLDFIELD R H. An analytic assessment of subsidies to bus services[J]. Transportation Science,1986,20(3) :200-212.
5BLADIKAS A K,CROWELL W H. Pricing options for urban transportation models[A]. Transportation Research Record 1012 [C]. Washington D C: TRB,1985.23-30.
6NASH C A. Integration of public transport: an economic assessment[A]. Bus Deregulation and Privatization[C]. Aldershot: Gower Publishing Group, 1988.35-43.
7MUNIZAGA M A,HEYDECKER B G,Ortúzar Juan de Dios. Representation of heteroskedasticity in discrete choice models [J]. Transportation Research,2001,35 (3): 219-240.
