{"title": "Fertility change on the American frontier", "covers": [8452607], "subject_places": ["Utah", "West (U.S.)"], "subjects": ["History", "Human Fertility", "Population", "Fertility, human", "Utah, history", "West (u.s.), history", "History, 19th Century", "History of Medicine", "Fertility", "Birth Rate"], "key": "/works/OL374330W", "authors": [{"type": {"key": "/type/author_role"}, "author": {"key": "/authors/OL11622A"}}], "subject_times": ["19th century"], "type": {"key": "/type/work"}, "latest_revision": 5, "revision": 5, "created": {"type": "/type/datetime", "value": "2009-10-27T18:14:33.340513"}, "last_modified": {"type": "/type/datetime", "value": "2025-09-05T17:39:56.375395"}}