Sears, J. H. The Physical Geography, Geology, Mineralogy and Paleontology of Essex County, Massachusetts.
Cita Chicago Style (17a ed.)Sears, John Henry. The Physical Geography, Geology, Mineralogy and Paleontology of Essex County, Massachusetts.
Cita MLA (9a ed.)Sears, John Henry. The Physical Geography, Geology, Mineralogy and Paleontology of Essex County, Massachusetts.
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