Most metadata registered with Crossref is publicly available but by default references deposited for a given DOI are only available to the current owner of the DOI or to OAI-PMH subscribers (when given permission by the current publisher).
Members may elect to distribute references to the public, meaning references included in your metadata record will be available through our metadata channels including the REST API and UNIXSD query results.
If you want to make all references publicly available (this is recommended) contact us and we'll enable reference distribution for your prefix (or prefixes). If you want to enable reference distribution for individual items, you can include a 'reference_distribution_opt' flag within your <journal_article> element, for example:
<journal_article publication_type="full_text" reference_distribution_opts="any">