The geology of Lehigh and Northampton Counties. - Geological Survey of Pennsylvania; D'Invilliers, Edward Vincent, 1857- (Harrisburg, Board of Commissioners for the Second Geological Survey, 1883)
Atlas sheets also illustrate D3, v. 2: The geology of the South Mountain belt of Berks County, by E.V. D'Invilliers.
Keywords: Geology -- Pennsylvania -- Lehigh County; Geology -- Pennsylvania -- Northampton County