8Yang H,Wong S C,Wong K I. Demand-supply equi- librium of taxi services in a network under competi- tion and regulation[J]. Transportation Research Part B: Methodological, 2002,36 (9):799-819.
9Laneaster K J. A new approach to consumer theory[J]. Journal of Political Economy, 1966,74(1) : 132-157.
10Rosen S. Hedonic prices 'and implicit markets:Product differentiation in pure competition[J]. Journal of Po- litical Economy, 1974,82(1) : 35-55.