1. Bulletin Publication/Creation: Baltimore, Md. : Published by permission of the Director, U.S. Geological Survey, 1965- Resource Type: Journal, Newspaper or Serial Access & Availability: Loading
2. Report of investigations Publication/Creation: Baltimore : Maryland Geological Survey, 1965- Resource Type: Journal, Newspaper or Serial Access & Availability: Loading
3. The geology of Harford County, Maryland Author/Creator: Southwick, D. L. 1936- (David Leroy) Publication/Creation: Baltimore : Maryland Geological Survey, 1969 Resource Type: Book Access & Availability: Loading