{"id":"obr:work:perpetual-motion","slug":"perpetual-motion","url":"https://openbookrank.com/en/book/perpetual-motion","urls":{"en":"https://openbookrank.com/en/book/perpetual-motion"},"title":"Perpetual Motion","titles":{"en":"Perpetual Motion","fr":"Mouvement perpétuel","uk":"Вічний двигун (Спрег де Кемп)"},"author":{"id":"obr:author:null","name":"L. Sprague de Camp","api":"https://openbookrank.com/api/v1/authors/null.json"},"year":1950,"pages":null,"originalLanguage":null,"identifiers":{"wikidata":"Q7169539","openLibrary":null,"isbn13":null,"isbns":[],"isbnByLanguage":{},"googleBooks":null,"hardcover":null,"amazon":null},"score":{"value":null,"scale":10,"ratings":0,"confidence":null,"rawAverage":null,"method":"bayesian-weighted-average","priorWeight":147,"minRatings":50,"methodology":"https://openbookrank.com/en/methodology"},"sources":[],"ranks":[],"popularity":{"ratingsPercentile":0,"wikipediaPageviews":null,"editions":null},"series":{"id":"obr:series:viagens-interplanetarias","slug":"viagens-interplanetarias","title":"Viagens Interplanetarias","position":null,"volumes":9,"api":"https://openbookrank.com/api/v1/series/viagens-interplanetarias.json"},"awards":[],"adaptations":[],"similar":[],"citation":"BookRank (openbookrank.com) lists \"Perpetual Motion\" by L. Sprague de Camp but does not score it: it has fewer than 50 reader ratings (snapshot 2026-10-28).","snapshot":"2026-10-28","license":"CC-BY-4.0"}