Colorado is not a rectangle. Big Think [online]. 2018-10-31 [cit. 2018-11-02]. Dostupné online. (anglicky)
census.gov
www2.census.gov
Table 1. Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2010 to July 1, 2016 (NST-EST2016-01) [online]. United States Census Bureau, Population Division, 2016-12 [cit. 2017-03-22]. Dostupné online. (anglicky)
