Data sources
The catalogue is built from open databases that allow reuse. Here is where records come from, under which licence, and when they were extracted.
- MusicBrainz
Records: releases, artists, barcodes.
Licence: CC0 1.0
Extracted on September 16, 2026
- Discogs (data dumps)
Records: pressings, labels, catalogue numbers.
Licence: CC0 1.0
Extracted on September 1, 2026
- Open Library
Books: editions, authors, covers, series.
Licence: CC0 1.0
Extracted on September 16, 2026
- Cover Art Archive
Record sleeves.
Licence: Cover Art Archive
Extracted on September 16, 2026
- Bibliothèque nationale de France, data.bnf.fr
Books published in France.
Licence: Licence Ouverte / Open Licence 2.0
Extracted on September 17, 2026
- Biblioteca Nacional de España
Books published in Spain.
Licence: CC0 1.0
Extracted on September 18, 2026
- 国立国会図書館 (National Diet Library)
Books published in Japan.
Licence: 国立国会図書館 書誌データの利用
Extracted on September 18, 2026
出典：国立国会図書館「NDLサーチ」OAI-PMH全件ファイル（2026年9月5日）を加工して作成
- 國家圖書館 (National Central Library, Taiwan)
Books published in Taiwan since 2024.
Licence: 政府資料開放授權條款－第1版
Extracted on September 18, 2026
國家圖書館 2024–2026 臺灣出版新書預告書訊（資料集 6730），依政府資料開放授權條款－第1版釋出
Data from these sources has been reformatted, deduplicated and merged by What I Already Own, and may therefore differ from its original publication.
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