Parecki, A. (2012) Everywhere I've Been: Data Portraits Powered by 3.5 years of data and 2.5 million GPS Points [Various data sets of maps across Portland/San Francisco]. Retrieved from https://geoloqi.com/blog/2012/03/data-portraits-powered-by-3-5-years-of-data-and-2-5-million-gps-points/