How to check which Techstack patchsets have been applied

SET head off Lines 120 pages 100
col n_patch format A65
col bug_number format A10
col patch_name format A10
spool atg_pf_ptch_level.txt
select ' atg_pf ' FROM dual;
/

select bug_number, decode(bug_number,
'3438354', '11i.ATG_PF.H'
,'4017300' ,'11i.ATG_PF.H.RUP1'
,'4125550' ,'11i.ATG_PF.H.RUP2'
,'4334965' ,'11i.ATG_PF.H RUP3'
,'4676589' ,'11i.ATG_PF.H RUP4'
,'5382500' ,'11i.ATG_PF.H RUP5 HELP'
,'5473858' ,'11i.ATG_PF.H.5'
,'5674941' ,'11i.ATG_PF.H RUP5 SSO Integrat'
,'5903765' ,'11i.ATG_PF.H RUP6'
,'6117031' ,'11i.ATG_PF.H RUP6 SSO 10g Integration'
,'6330890' ,'11i.ATG_PF.H RUP6 HELP'
) n_patch, last_update_date
FROM ad_bugs
WHERE bug_number
IN ( '3438354', '4017300', '4125550', '4334965', '4676589', '5382500', '5473858', '5674941', '5903765', '6117031', '6330890' );