http://www.rssboard.org/rss-specification 720 XTF Search Results (docsPerPage=100;f277-subject=Petrology -- Michigan) https://catalog.wrhs.org/collections/search?docsPerPage%3D100;f277-subject%3DPetrology%20--%20Michigan Results for your query: docsPerPage=100;f277-subject=Petrology -- Michigan Thu, 01 Jan 1970 12:00:00 GMT Upper Peninsula, 1878-1880: accompanied by a geological map. Rominger, Carl Ludwig, 1820-1907, Michigan Geological Survey. 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