1. ATSDR (Agency for Toxic Substances and Disease Registry). 2010. Atlanta, GA, USA: Compendium of papers on MRLs and health effects. US Department of Health and Human Services. Available athttp://www.atsdr.cdc.gov/
2. BC Oil and Gas Commission. 2010. “Fracturing (Fraccing) and Disposal of Fluids. Oil and Gas Commission Fact Sheet”. Available athttp://www.bcogc.ca/documents/publications/Fact%20Sheets/Fracturing_and_Disposal_of_Fluids_FINAL.pdf
3. The Ozone Component of Global Change: Potential Effects on Agricultural and Horticultural Plant Yield, Product Quality and Interactions with Invasive Species
4. CH2MHILL. Review of Oil and Gas Operation Emissions and Control Options. Final report. Prepared for Colorado Department of Public Health and Environment Air Pollution Control Division. Denver, CO, USA.