Sources
Every answer starts with evidence
The current release prioritizes government guidance, legislation and national-library catalog records.
United States Copyright Office: Circular 15ADuration and renewal rules for works created and published in the United States.https://www.copyright.gov/circs/circ15a.pdfUnited States Copyright Office: Title 17, Chapter 3Current statutory duration provisions, including corporate and unpublished works.https://www.copyright.gov/title17/92chap3.htmlUnited States Copyright Office: Music Modernization ActFederal protection schedule for sound recordings fixed before 15 February 1972.https://www.copyright.gov/music-modernization/faq.htmlUK Intellectual Property OfficeGeneral terms, films, recordings and the Peter Pan royalty right.https://www.gov.uk/government/publications/copyright-notice-duration-of-copyright-term/copyright-notice-duration-of-copyright-termUK legislation: 2013 term regulationsThe recording-term extension and transitional protection rules.https://www.legislation.gov.uk/uksi/2013/1782/contentsEUR-Lex: Directive 2006/116/ECEuropean Union copyright terms, films and third-country shorter-term treatment.https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32006L0116EUR-Lex: Directive 2011/77/EUThe European Union sound-recording term extension and transition provisions.https://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:32011L0077Government of Canada: Copyright Act, section 23Current fixation, publication and maximum sound-recording terms.https://laws-lois.justice.gc.ca/eng/acts/C-42/section-23.htmlNational Library of AustraliaCopyright duration guidance and transitional examples.https://www.library.gov.au/services/copyright-library-collections/how-long-does-copyright-lastJapan Agency for Cultural AffairsCopyright term overview, films, organizational works and the 2018 extension.https://www.bunka.go.jp/english/policy/copyright/system/Library of CongressCatalog records and essays for representative works.https://www.loc.gov/WikidataCC0 work, creator, death-date and publication-date metadata for the expanded catalogue.https://www.wikidata.org/wiki/Wikidata:LicensingProject GutenbergOfficial offline catalogue entries used as a second metadata source for imported works.https://www.gutenberg.org/ebooks/offline_catalogs.html