Indiana Limestone Institute of America, Inc.

https://www.iliai.com

Natural Stone Institute

https://www.naturalstoneinstitute.org/

Precast/Prestressed Concrete Institute

https://www.pci.org

National Precast Concrete Association

https://www.precast.org

National Building Granite Quarries Association

https://www.nbgqa.com

U.S. Geological Survey

https://www.usgs.gov/centers/nmic/mineral-industry-indiana#myb