ExtractValue(marcxml,'//datafield[@tag="100"]/subfield[@code="9"]') as first_author,
ExtractValue(marcxml,'//datafield[@tag="700"]/subfield[@code="9"]') as other_authors,
ExtractValue(marcxml,'//datafield[@tag="942"]/subfield[@code="t"]') as category,
ExtractValue(marcxml,'//datafield[@tag="100"]/subfield[@code="9"]') as first_author,
ExtractValue(marcxml,'//datafield[@tag="700"]/subfield[@code="9"]') as other_authors,
ExtractValue(marcxml,'//datafield[@tag="942"]/subfield[@code="t"]') as category,