{"schema_version":"bf_book_companion_v1","release_id":"20260406T231758Z","book":{"amazon_purchase_url":"https://www.amazon.com/dp/B00CBDC2T6?tag=bookfrontier-20","asin":"B00CBDC2T6","authors":["Algis Budrys"],"book_id":"9781625588739","canonical_url":"https://bookfrontier.com/books/9781625588739","cover_image_url":"https://img.bookfrontier.com/9781625588739.jpg?v=20260406T231758Z%3A2026-04-06T23%3A17%3A58Z","description":"He was looking for a privacy his strange personality needed, and never quite seemed to achieve it. All his efforts were, somehow, great triumphs of the race, and great failures for him!","forthcoming":false,"isbn13":"9781625588739","publication_date":"20130325","publisher":"Start Publishing LLC","slug":"citadel","subtitle":"Kindle Edition","title":"Citadel"},"discovery":{"categories":{"all":[{"bisac_code":"FIC028020","confidence_band":"medium","label":"Hard Sci-Fi","score":0.7723,"source":"bisac_hint_model"},{"bisac_code":"FIC028030","confidence_band":"medium","label":"Space Opera","score":0.7637,"source":"bisac_hint_model"},{"bisac_code":"FIC028010","confidence_band":"medium","label":"Sci-Fi Adventure","score":0.7591,"source":"bisac_hint_model"}],"hint":[{"bisac_code":"FIC028020","confidence_band":"medium","label":"Hard Sci-Fi","score":0.7723,"source":"bisac_hint_model"},{"bisac_code":"FIC028030","confidence_band":"medium","label":"Space Opera","score":0.7637,"source":"bisac_hint_model"},{"bisac_code":"FIC028010","confidence_band":"medium","label":"Sci-Fi Adventure","score":0.7591,"source":"bisac_hint_model"}],"publisher":[{"bisac_code":"FIC002000","confidence_band":"high","label":"Action & Adventure","score":1,"source":"onix_publisher_code"},{"bisac_code":"FIC009100","confidence_band":"high","label":"Fantasy Adventure","score":1,"source":"onix_publisher_code"},{"bisac_code":"FIC027260","confidence_band":"high","label":"Romance Adventure","score":1,"source":"onix_publisher_code"}]},"genres":[{"label":"Hard Sci-Fi","score":0.7723,"slug":"hard-sci-fi"},{"label":"Space Opera","score":0.7637,"slug":"space-opera"},{"label":"Sci-Fi Adventure","score":0.7591,"slug":"sci-fi-adventure"}],"reader_fit":["Good for readers who enjoy Hard Sci-Fi","Good for readers interested in personal development","Good for fans of Science Fiction"],"related_lists":[{"intro":"","slug":"shelf-fic028020-hard-science-fiction","title":"Hard Science Fiction Books","url":"https://bookfrontier.com/lists/shelf-fic028020-hard-science-fiction"}],"series":null,"similar_books":[{"authors":["Keith Laumer"],"book_id":"9781625587329","cover_image_url":"https://img.bookfrontier.com/9781625587329.jpg?v=20260406T231758Z%3A2026-04-06T23%3A17%3A58Z","score":17.2572,"title":"Greylorn","url":"https://bookfrontier.com/books/9781625587329"},{"authors":["Alan E. Nourse"],"book_id":"9781681465128","cover_image_url":"https://img.bookfrontier.com/9781681465128.jpg?v=20260406T231758Z%3A2026-04-06T23%3A17%3A58Z","score":17.2018,"title":"Derelict","url":"https://bookfrontier.com/books/9781681465128"},{"authors":["Robert Sheckley"],"book_id":"9781682999301","cover_image_url":"https://img.bookfrontier.com/9781682999301.jpg?v=20260406T231758Z%3A2026-04-06T23%3A17%3A58Z","score":17.1912,"title":"The Hour of Battle","url":"https://bookfrontier.com/books/9781682999301"},{"authors":["Clifford D. Simak"],"book_id":"9781627930130","cover_image_url":"https://img.bookfrontier.com/9781627930130.jpg?v=20260406T231758Z%3A2026-04-06T23%3A17%3A58Z","score":17.1885,"title":"Project Mastodon","url":"https://bookfrontier.com/books/9781627930130"},{"authors":["Leigh Brackett"],"book_id":"9781649740984","cover_image_url":"https://img.bookfrontier.com/9781649740984.jpg?v=20260406T231758Z%3A2026-04-06T23%3A17%3A58Z","score":17.1724,"title":"Outpost on Io","url":"https://bookfrontier.com/books/9781649740984"},{"authors":["Clifford D. Simak"],"book_id":"9781682991848","cover_image_url":"https://img.bookfrontier.com/9781682991848.jpg?v=20260406T231758Z%3A2026-04-06T23%3A17%3A58Z","score":17.1563,"title":"Second Childhood","url":"https://bookfrontier.com/books/9781682991848"},{"authors":["Ray Bradbury"],"book_id":"9781681464992","cover_image_url":"https://img.bookfrontier.com/9781681464992.jpg?v=20260406T231758Z%3A2026-04-06T23%3A17%3A58Z","score":17.1382,"title":"A Little Journey","url":"https://bookfrontier.com/books/9781681464992"},{"authors":["H. Beam Piper"],"book_id":"9781682999264","cover_image_url":"https://img.bookfrontier.com/9781682999264.jpg?v=20260406T231758Z%3A2026-04-06T23%3A17%3A58Z","score":17.1335,"title":"The Answer","url":"https://bookfrontier.com/books/9781682999264"}],"topics":[{"evidence_refs":["keyword:privacy themed science fiction"],"label":"Science","score":0.2945,"slug":"science"},{"evidence_refs":["keyword:personal privacy struggle"],"label":"Personal","score":0.0965,"slug":"personal"}],"what_you_get":["Themes: Science, Personal.","Reading lane: Hard Sci Fi and Space Opera.","Publisher: Start Publishing LLC."]},"llm_signals":null,"source_presence":{"amazon":true,"book_detail":true,"goodreads":true,"llm_signals":false,"similarity_seed":true},"stats":{"amazon_ratings_count":0,"goodreads_ratings_count":48,"goodreads_reviews_count":6,"quality_score":0.8507}}