Southworth, S. (2004). Geology of the national capital region - field trip guidebook. US Geological Survey circular 1264.
Chicago Style CitationSouthworth, Scott. "Geology of the National Capital Region - Field Trip Guidebook." US Geological Survey Circular 1264 2004.
MLA CitationSouthworth, Scott. "Geology of the National Capital Region - Field Trip Guidebook." US Geological Survey Circular 1264 2004.
Warning: These citations may not always be 100% accurate.