OAI-PMH repo 'authority record' items missing

Omeka S Modules
1

Hello,
I am running Omeka S on Ubuntu, it works fine. I need the OAI PMH repository so that I can send journal articles to scholarly indexers. The metadata of the article items is well represented, but ‘authority record’ items, like authors, and relations to journal issues, plus SKOS thesaurus entity items are not.
Example:

      <dcterms:title>Mit jelent a digitális filológia a szemantikus web korában?</dcterms:title>
      <dcterms:creator />
      <dcterms:subject>digitális filológia</dcterms:subject>
      <dcterms:publisher>Magyar Tudományos Akadémia</dcterms:publisher>
      <dcterms:type>articles</dcterms:type>
      <dcterms:language>Hungarian</dcterms:language>
      <dcterms:alternative>A DigiPhil projektról</dcterms:alternative>
      <dcterms:created>2016</dcterms:created>
      <dcterms:isPartOf />
      <dcterms:spatial>Budapest</dcterms:spatial>
      <dcterms:identifier>http://localhost/api/items/17</dcterms:identifier>
      <dcterms:identifier>http://localhost/files/original/17/bebd2e1ffed05efd1dcbedb9f53afe698628ee6c.pdf</dcterms:identifier>
    </oai_dcterms:dcterms>

These relations are there on the API interface:

“dcterms:isPartOf”:
[{“type”:“resource:item”,“property_id”:33,“property_label”:“Is Part Of”,“is_public”:true,"@id":“http://localhost/api/items/16",“value_resource_id”:16,“value_resource_name”:“items”,“url”:null,“display_title”:"Magyar Tudom\u00e1ny”}]

Is it a way to map these as well?

Best
Gábor