Colton, R. B., & Fitch, H. R. (1974). Map showing potential sources of gravel and crushed-rock aggregate in the Boulder-Fort Collins-Greeley area, Front Range urban corridor, Colorado. U.S. Geological Survey.
Chicago Style (17th ed.) CitationColton, Roger B., and Harold R. Fitch. Map Showing Potential Sources of Gravel and Crushed-rock Aggregate in the Boulder-Fort Collins-Greeley Area, Front Range Urban Corridor, Colorado. Reston, Va.: U.S. Geological Survey, 1974.
MLA (9th ed.) CitationColton, Roger B., and Harold R. Fitch. Map Showing Potential Sources of Gravel and Crushed-rock Aggregate in the Boulder-Fort Collins-Greeley Area, Front Range Urban Corridor, Colorado. U.S. Geological Survey, 1974.
Warning: These citations may not always be 100% accurate.