Query Oracle hidden/underscore parameters

SELECT a.ksppinm "Parameter",
               a.ksppdesc "Description",
               b.ksppstvl "Session Value",
               c.ksppstvl "Instance Value"
FROM x$ksppi a, x$ksppcv b, x$ksppsv c
WHERE a.indx = b.indx
     AND a.indx = c.indx
    AND a.ksppinm LIKE '%%';