Crossref

Crossref provides shared infrastructure for linking scholarly research. Its website explains digital object identifiers, research metadata and the services used by publishers and other organisations to register and connect research outputs. Readers can use its metadata search and related tools to identify works, while organisations can find documentation about membership, registration and maintaining their records.

The service is operated by the nonprofit Publishers International Linking Association. Crossref metadata helps connect a citation or identifier with information supplied by a participating organisation and, where available, the location of a research output. It is a discovery and linking service rather than a universal collection of free full texts. The website is useful for checking publication details, understanding DOI infrastructure and finding the relevant technical documentation or public metadata interface.