1. Surficial geology of the Ayer quadrangle, Massachusetts [cartographic material] Yale Public content 1953. 2011-11-29T19:01:09Z. 2012-03-05T17:16:33Z. Jahns, Richard H. (Richard Henry), 1915-1983. U.S. Geological Survey. English. Public. Massachusetts, Middlesex County, and Worcester County.