1. Toll Facilities in the United States 2013
2. Samuel , P. 2009 New Zealand gets first modern pike-video tolled TOLLROADSnews
3. Samuel , P. 2007 Central toll in Stockholm restarts with IR cameras only, 700k transponders dumped TOLLROADSnews
4. 2014 Specialty License Plate Rankings, Florida Department of Highway Safety and Motor Vehicles http://www.flhsmv.gov/specialtytags/tagsales.pdf