1. The 1990 Amendments to the Clean Air Act, S. 1630, Title I – Provisions for Attainment and Maintenance of National Ambient Air Quality Standards, Sec. 103. Subpart 2 – Additional Provisions for Ozone Nonattainment Areas, Section 182(c)(1) – Enhanced Monitoring, available from http://uscode.house.gov/statutes/pl/101/549.pdf, last accessed March 21, 2016
2. Code of Federal Regulations (CFR) Forty (40), Part 58 – Ambient Air Quality Surveillance, Subpart G – Federal Monitoring, Appendix D – Network Design Criteria for Ambient Air Quality Monitoring, 5 – Design Criteria for Photochemical Assessment Monitoring Stations (PAMS), available from http://www.ecfr.gov/cgi-bin/retrieveECFR?n=40y6.0.1.1.6, last accessed March 21, 2016
3. Federal Register , volume 62, number 138, National Ambient Air Quality Standards for Ozone: Final Rule, Washington, D.C., July 18, 1997, pp. 38855–38896, available from https://www.gpo.gov/fdsys/pkg/FR-1997-07-18/html/97-18580.htm, last accessed March 21, 2016
4. Federal Register , volume 73, number 60, National Ambient Air Quality Standards for Ozone: Final Rule, Washington, D.C., March 27, 2008, pp. 16436–16514, available from https://www.gpo.gov/fdsys/pkg/FR-2008-03-27/pdf/E8-5645.pdf, last accessed March 21, 2016
5. Federal Register , volume 80, number 206, National Ambient Air Quality Standards for Ozone: Final Rule, Washington, D.C., October 26, 2015, pp. 65292–65468, available from https://www.gpo.gov/fdsys/pkg/FR-2015-10-26/pdf/2015-26594.pdf, last accessed March 21, 2016