1. White C. Pa. Native Takes Helm at Range Resources. Centre Daily Times online edition Marcellus Drill Bits section (30 Jun 2011). Available: http://tinyurl.com/6yo5gg5 [accessed 6 Jul 2011].
2. EIA. Natural Gas Data. Natural Gas Annual Supply & Disposition by State [website]. Washington DC:U.S. Energy Information Administration U.S. Department of Energy (29 Jun 2011). Available: http://tinyurl.com/5w99mee [accessed 6 Jul 2011].
3. EIA. Assumptions to the Annual Energy Outlook 2011. Washington DC:U.S. Energy Information Administration U.S. Department of Energy (Jul 2011). Available: http://tinyurl.com/5rlh7sw [accessed 6 Jul 2011].
4. Committee on Energy and Commerce Minority Staff. Chemicals Used in Hydraulic Fracturing. Washington DC:Committee on Energy and Commerce Minority Staff U.S. House of Representatives (Apr 2011). Available: http://tinyurl.com/3ban29n [accessed 6 Jul 2011].
5. NTP. Report on Carcinogens Twelfth Edition 2011. Research Triangle Park NC:National Toxicology Program Public Health Service U.S. Department of Health and Human Services (2011). Available: http://tinyurl.com/6446t85 [accessed 6 Jul 2011].