schema_version: "1.0" sources: - citation_key: handbook-2026ed type: institutional-document published_date: value: "2026-09-15" precision: day open_ended: false provenance: method: crossref_lookup confidence: high effective_date_range: start: value: "2026-09-15" precision: day open_ended: false provenance: method: crossref_lookup confidence: high end: value: null precision: unknown open_ended: true provenance: method: user_override confidence: high events: []