http://www.rssboard.org/rss-specification 720 XTF Search Results (docsPerPage=100;f4-subject=Geology, Economic) https://catalog.wrhs.org/collections/search?docsPerPage%3D100;f4-subject%3DGeology,%20Economic Results for your query: docsPerPage=100;f4-subject=Geology, Economic Thu, 01 Jan 1970 12:00:00 GMT The economical geology of the region of Cheboygan and old Mackinac, in the counties of Presque isle, Cheboygan, and Emmet, state of Michigan. Winchell, N. H. (Newton Horace), 1839-1914 https://catalog.wrhs.org/collections/view?docId=marc/skclmarc202890322046876.mrc https://catalog.wrhs.org/collections/view?docId=marc/skclmarc202890322046876.mrc Thu, 01 Jan 1970 12:00:00 GMT