Query to find item cross-references :

SELECT   msi.segment1 item,
           mcr.cross_reference_type reference_type,
           mcr.cross_reference,
           mcr.description
    FROM   mtl_cross_references mcr, mtl_system_items msi
   WHERE       mcr.cross_reference_type = 'Vendor'
           AND mcr.inventory_item_id = msi.inventory_item_id
           AND mcr.organization_id = msi.organization_id
ORDER BY   1, 2
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