With reftables(reftabname,PRIORITY) as(
Select reftabname,1 from syscat.references as refx where refx.tabname='PROJECT'
union all
Select ref2.reftabname,reftables.PRIORITY+1 from reftables,syscat.references ref2 where reftables.reftabname=ref2.tabname
)
Select * from reftables ORDER BY PRIORITY DESC;

With reftables(tabname,PRIORITY) as(  
Select tabname,1 from syscat.references as refx where refx.reftabname='PROJECT'  
union all  
Select ref2.tabname,reftables.PRIORITY+1 from reftables,syscat.references ref2 where reftables.tabname=ref2.reftabname and  reftables.PRIORITY<2
)  
Select distinct * from reftables ORDER BY PRIORITY DESC;

reftables.PRIORITY<2