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 # Sources
+
+The core metadata bootstrap sources, by entity type, are:
+
+- `releases`: Crossref metadata, with DOIs as the primary identifier, and
+  PubMed (central), Wikidata, and [CORE]() identifiers cross-referenced
+- `containers`: munged metadata from the DOAJ, ROAD, and Norwegian journal
+  list, with ISSN-Ls as the primary identifier. ISSN provides an "ISSN to
+  ISSN-L" mapping to normalize electronic and print ISSN numbers.
+- `creators`: ORCID metadata and identifier.
+
+Initial `file` metadata and matches (file-to-release) come from earlier
+Internet Archive matching efforts, and in particular efforts to extra
+bibliographic metadata from PDFs (using GROBID) and fuzzy match (with
+conservative settings) to Crossref metadata.
+
+[CORE]: https://core.ac.uk
+
+The intent is to continuously ingest and merge metadata from a small number of
+large (~2-3 million more more records) general-purpose aggregators and catalogs
+in a centralized fashion, using bots, and then support volunteers and
+organizations in writing bots to merge high-quality metadata from field or
+institution-specific catalogs.
+
+Progeny information (where the metadata comes from, or who "makes specific
+claims") is stored in edit metadata in the data model. Value-level attribution
+cna be achived by looking at the full edit history for an entity as a series of
+patches.
+