1. Alaska SIP. 18 AK ADC 50.045(d). Available at: http://yosemite.epa.gov/r10/airpage.nsf/701092a6cfd3176c88256b6e000337d9/f9508a416b09305088256a080069469c!OpenDocument.
2. Characterization of Particulate Matter (PM10) in Roda, Virginia;Aneja,2009
3. Appalachian Regional Commission. County Economic Status in Appalachia, FY 2010. http://www.arc.gov/assets/maps/related/County-Economic-Status_FY2010_Map.pdf.
4. Trace metal composition of airborne particulate matter in the coal mining and non-mining areas of Dhanbad region;Dubey,2012
5. Modes of occurrence of environmentally-sensitive trace elements in coal;Finkelman,1995