<record>
  <controlfield tag="001">1851</controlfield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">missing-mass</subfield>
  </datafield>
  <datafield tag="653" ind1="1" ind2=" ">
    <subfield code="a">dark matter</subfield>
  </datafield>
</record>