1. Ahern JJ, Frazier JA (1982) Water quality changes at underground coal gasification sites—a literature review. Water Resour Res Inst, University of Wyoming, Laramie, Wyoming. http://uwdigital.uwyo.edu/islandora/object/wyu:4915/datastream/OBJ/download/Water_Quality_Changes_At_Underground_Coal_Gasification_Sites_-_A_Literature_Review_-_Final_Report_.pdf . Accessed 23 Nov 2015
2. Brown RL, Parizek RR (1971) Shallow ground water flow systems beneath strip and deep coal mines at two sites, Clearfield County, Pennsylvania. College of Earth and Mineral Sciences, Special Research Report SR-84, Pennsylvania State University, p 216
3. Carras JN, Day SJ, Saghafi A, Williams DJ (2009) Greenhouse gas emissions from low-temperature oxidation and spontaneous combustion at open-cut coal mines in Australia. Int J Coal Geol 78:161–168
4. Cassells CJS, Genderen JL (1995) Thermal modelling of underground coal fires in northern China. Remote sensing in action. In: Proceedings of the 21st annual conference of the Remote Sensing Society, 11–14 September 1995, pp 544–551
5. Dixon DY, Rauch HW (1988) Study of quantitative impacts to groundwater associated with longwall coal mining at three mine sites in the northern West Virginia area. In: Proceedings 7th international conference on ground control in mining, West Virginia University, August 1998, pp 321–335