Foreign Keys Constraints created without accompanying index

#ORACLE
SELECT
    a.constraint_name                   cons_name ,
    a.table_name                        tab_name ,
    b.column_name                       cons_column ,
    NVL(c.column_name,'***No Index***') ind_column
FROM
    user_constraints a
JOIN
    user_cons_columns b
ON
    a.constraint_name = b.constraint_name
LEFT OUTER JOIN
    user_ind_columns c
ON
    b.column_name = c.column_name
AND b.table_name = c.table_name
WHERE
    constraint_type = 'R' and
    c.column_name is null
ORDER BY
    2,1;