Query to extract resigned staff salaries

Hi,

As below is the query developed for resigned staff details, only stuck at extracting salary column of ex-staff  it is showing multiple record, can any expert review the query and revert back with correction.

SELECT DISTINCT

     a.person_id, 

     a.employee_number   "EMP NO",

     a.first_name      || ' '      || a.last_name name,

     TO_CHAR(a.start_date,'DD-MON-YYYY') "JOINING DATE",

     g.name              grade,

     jb.name             Job,

     ppg.SEGMENT1        Division,

     ppg.SEGMENT2        Department,

     loc.DESCRIPTION     "location",    

     TO_CHAR(b.notified_termination_date,'DD-MON-YYYY') "RESIGN DATE ",

     TO_CHAR(b.actual_termination_date,'DD-MON-YYYY') "LAST WORKING DAY",

     TO_CHAR(b.last_standard_process_date,'DD-MON-YYYY') last_process_date,