1. U.S. Department of the Interior, U.S. Geological Survey, Minerals Information, Jan. 12, 2005, http://www.minerals.usgs.gov/minerals/pubs/commodity/iron_&_steel_slag/
2. H.G. van Oss: U.S. Geological Survey Minerals Yearbook, 2003, 69.1–69.3, June 30, 2005, http://www.minerals.usgs.gov/minerals/pubs/commodity/iron_&_steel_slag/islagmyb03.pdf
3. National Slag Association [brochure], June 30, 2005, http://www.nationalslagassoc.org/PDF_files/SSPremAgg.pdf
4. D.W. Lewis: Report No. MF 182-6, National Slag Association, Pleasant Grove, UT
5. Missouri Department of Transportation, Apr. 14, 2004, http://www.modot.org/business/standards_and_specs/nov2004specbook/Sec1002.pdf