{"notes": {"type": "/type/text", "value": "1"}, "title": "Investigation of Track Rock Corundum Mine Union County, ga.", "authors": [{"key": "/authors/OL160635A"}], "publish_date": "1948", "publishers": ["s.n"], "series": ["Report of investigations (United States. Bureau of Mines) -- 4309"], "contributions": ["Ballard, T."], "languages": [{"key": "/languages/eng"}], "publish_places": ["S.l"], "type": {"key": "/type/edition"}, "source_records": ["marc:marc_laurentian/openlibrary.mrc:497534812:786"], "key": "/books/OL21748716M", "works": [{"key": "/works/OL1509383W"}], "latest_revision": 4, "revision": 4, "created": {"type": "/type/datetime", "value": "2008-11-03T19:38:39.942068"}, "last_modified": {"type": "/type/datetime", "value": "2026-01-04T14:08:52.593397"}}