1. Geography and Geographic, Information Science, CyberGIS Center for Advanced, Digital and Spatial Studies, University of Illinois at Urbana-Champaign, Urbana, Illinois
2. Geography and Geographic, Information Science, CyberGIS Center for Advanced, Digital and Spatial Studies, National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Urbana, Illinois
3. CyberGIS Center for Advanced, Digital and Spatial Studies, National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Urbana, Illinois