Changes

* Flores, Verla R.  and A. Dudley Gardner. ''Forgotten Frontier: A History of Wyoming Coal Mining'' (1989) [http://www.questia.com/PM.qst?a=o&d=85688689 online edition]

* Flores, Verla R.  and A. Dudley Gardner. ''Forgotten Frontier: A History of Wyoming Coal Mining'' (1989) [http://www.questia.com/PM.qst?a=o&d=85688689 online edition]

* Lauver, Fred J. "A Walk Through the Rise and Fall of Anthracite Might," ''Pennsylvania Heritage Magazine'' 27#1 (2001) [http://www.phmc.state.pa.us/ppet/miningmuseum/page1.asp?secid=31 online edition]

* Lauver, Fred J. "A Walk Through the Rise and Fall of Anthracite Might," ''Pennsylvania Heritage Magazine'' 27#1 (2001) [http://www.phmc.state.pa.us/ppet/miningmuseum/page1.asp?secid=31 online edition]

* Priscilla Long, ''Where the Sun Never Shines: A History of America's Bloody Coal Industry'' Paragon, 1989.

* Long, Priscilla.  ''Where the Sun Never Shines: A History of America's Bloody Coal Industry'' (1989).

* Nelson, Robert H. ''The Making of Federal Coal Policy'' (1983) [http://www.questia.com/PM.qst?a=o&d=51646786  online edition]

* Nelson, Robert H. ''The Making of Federal Coal Policy'' (1983) [http://www.questia.com/PM.qst?a=o&d=51646786  online edition]

* Netschert, Bruce C.  and Sam H. Schurr, ''Energy in the American Economy, 1850-1975: An Economic Study of Its History and Prospects.'' [http://www.questia.com/PM.qst?a=o&d=9239758 (1960) online]

* Netschert, Bruce C.  and Sam H. Schurr, ''Energy in the American Economy, 1850-1975: An Economic Study of Its History and Prospects.'' [http://www.questia.com/PM.qst?a=o&d=9239758 (1960) online]