Identify table references

table-ref.sql

select
  distinct *
from
(
select
  upper(:table_name) tabela,
  'is refereced by' behaviour,
  b.table_name
from 
  all_constraints a,
  all_tables b
where  
  a.constraint_type = 'R' and
  a.table_name = b.table_name and
  b.owner = :owner and  
  a.r_constraint_name in 
    (select x.constraint_name from all_constraints x, all_tables y  
       where  x.constraint_type in ('P', 'U') and  x.table_name = UPPER(:table_name) and x.table_name = y.table_name and y.owner = :owner)
union all  
select 
  upper(:table_name) tabela,
  'has references to' behavior,
  a.table_name
from 
  all_constraints a,
  all_tables b
where   
  a.table_name = b.table_name and
  b.owner = :owner and
  constraint_name in 
    (select r_constraint_name from all_constraints x, all_tables y where y.owner = :owner and x.table_name = UPPER(:table_name) and y.table_name = x.table_name)
)
order by 1,2;