Query to find Manufacturer items :

SELECT   mm.manufacturer_name,
           mp.mfg_part_num,
           mp.description,
           msi.segment1 inv_item,
           msi.description item_desc
    FROM   mtl_system_items msi, mtl_mfg_part_numbers mp, mtl_manufacturers mm
   WHERE       mm.manufacturer_id = mp.manufacturer_id
           AND mp.inventory_item_id = msi.inventory_item_id
           AND mp.organization_id = msi.organization_id
ORDER BY   1, 2
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