McGrain, P. (1976). Tar sands (rock asphalt) of Kentucky: A review. Kentucky Geological Survey.
Chicago Style (17th ed.) CitationMcGrain, Preston. Tar Sands (rock Asphalt) of Kentucky: A Review. Lexington: Kentucky Geological Survey, 1976.
MLA (9th ed.) CitationMcGrain, Preston. Tar Sands (rock Asphalt) of Kentucky: A Review. Kentucky Geological Survey, 1976.
Warning: These citations may not always be 100% accurate.