1. TLC Fact Book (2014) 2014 Taxi Cab Fact Book. Retrieved from Taxi and Limousine Commission website http://www.nyc.gov/html/tlc/downloads/pdf/2014_tlc_factbook.pdf.
2. TLC Taxi Book (2018) TLC’s Rules and Local Laws Taxi book, Chapter 51. Retrieved from Taxi and Limousine Commission. http://www.nyc.gov/html/tlc/downloads/pdf/rule_book_current _chapter_51.pdf.
3. Gilbert, Get al, R. O. Bach, F. C. Dilorio, and F. D. Fravel.. (1976) Taxicab User Characteristics in Small and Medium-Size Cities. UMTA-NC-11-0003-76-1.
4. Changes in real incomes and the demand for taxicabs.;Williams;Transportation,1981
5. Schaller, Bruce. (2005) “A regression model of the number of taxicabs in US cities.” Journal of Public Transportation, 8(5), 4.