Xu, W. , Yangyang, Y. , Ying, L. , Zhenzhen, W.. "Operational Analysis of Urban Intelligent Transportation System and Strategies for Future Development - Taking Calling Service of Taxi in Wuhan as an Example". World Academy of Science, Engineering and Technology, Open Science Index 78, International Journal of Economics and Management Engineering, (2013), 7(6), 1540 - 1546.