1. American Public Transportation Association (2014) 2014 PUBLIC TRANSPORTATION FACT BOOK. Washington DC USA. http://www.apta.com/resources/statistics/Documents/FactBook/2014-APTA-Fact-Book.pdf
2. codatu (2015) PLANNING SUSTAINABLE MOBILITY IN THE AMMAN METROPOLITAN AREA (JORDAN). http://www.codatu.org/actualites/planning-sustainable-mobility-in-the-amman-metropolitan-area-jordan/
3. Davis J. (2017) VMT Hits Nominal High Approaches All-Time Per Capita Mark Eno Transportation Weekly Week of February 20 2017 Eno center for transportation https://www.enotrans.org/article/vmt-hits-nominal-high-approaches-time-per-capita-mark