"doe-shalegasprimer-2009" . "Modern Shale Gas Development in the United States: A Primer"^^ . "2009"^^ . "http://energy.gov/sites/prod/files/2013/03/f0/ShaleGasPrimer_Online_4-2009.pdf"^^ . "report" . . . . . . . . . _:genid1 . _:genid1 . _:genid1 . _:genid1 . _:genid2 . _:genid2 . _:genid2 . _:genid2 . _:genid3 . _:genid3 . _:genid3 . _:genid3 .