northcentralpa.com/category/category/gas-drilling

paenvironmentdigest.com/newsletter

responsibledrillingalliance.org

propublica.org/series/buried-secrets-gas-drillings-environmental-threat

earthworksaction.org/oil_and_gas.cfm

dothemountain.wordpress.com

depweb.state.pa.us/portal/server.pt/community/dep_home/5968

dep.state.pa.us/dep/deputate/minres/oilgas/new_forms/marcellus

dcnr.state.pa.us