http://www.cde.state.co.us/stateinfo/
Colorado tax structure
GA4.9/9/INTERNET
Research Publication No. 9, part 1 (PDF)
Research Publication No. 9, part 2 (PDF)
Research Publication No. 9-1 (PDF)
Research Publication No. 9-2, part 1 (PDF)
Research Publication No. 9-2, part 2 (PDF)
