INV Unit of measure listing

select 
uom.uom_class      uom_class, 
uom.unit_of_measure  uom_name, 
uom.uom_code       uom_code, 
umc.conversion_rate conv_rate, 
uom2.unit_of_measure base_name, 
uom2.uom_code            base_code,
uom.disable_date     uom_disable_dt
from 
 mtl_units_of_measure   uom,
 mtl_uom_conversions  umc, 
 mtl_units_of_measure  uom2
where 
umc.inventory_item_id = 0 
and 
uom.unit_of_measure = umc.unit_of_measure (+) 
and 
uom.uom_class = umc.uom_class(+) 
and 
( uom.uom_class = uom2.uom_class (+) 
   and 
   uom2.base_uom_flag = 'Y' )
order by uom.uom_class, 
                uom.unit_of_measure, 
                uom2.unit_of_measure