↑ Montrie, Chad (2003). To Save the Land and People: A History of Opposition to Surface Coal Mining in Appalachia. United States: The University of North Carolina Press. tr. 17. ISBN0-8078-2765-7.
1 2 Society for Mining, Metallurgy, and Exploration (U.S.). Basics of Metal Mining Influenced Water: Volume 1 of Management technologies for metal mining influenced water. SME, 2008. ISBN 0873352599. Trang 15-16.
↑ Peter Darling. SME Mining Engineering Handbook, Third Edition: Volume 1 of SME Mining Engineering Handbook. SME, 2011. ISBN 0873352645. Trang 405.
↑ Skelly and Loy, Penn Environmental Consultants, United States. Environmental Protection Agency. Processes, procedures and methods to control pollution from mining activities. U.S. Environmental Protection Agency, 1973. Trang 4.
