select * 
from  dba_constraints t
where t.constraint_type = 'R'
and   t.owner = 'CORPORATIVO'
and   t.r_constraint_name = (select t2.constraint_name
                             from  dba_constraints t2
                             where t2.constraint_type = 'P'
                             and   t2.table_name = 'UM_PERMISSAO_WEB'
                             and   t2.owner = 'CORPORATIVO')