Public Holiday and Calendar events join with employee assignments

Summary

Public Holiday and Calendar events in Exception of work schedule

Content

select eve.*

   FROM
   per_cal_event_coverage cov,
   per_calendar_events_tl ev,
   per_calendar_events eve

   where 1=1
   and cov.calendar_event_id = ev.calendar_event_id
   and ev.calendar_event_id = eve.calendar_event_id
   and eve.CATEGORY = 'PH'   --- 'Public Holiday

  Above query and tables are for calendar events that are having Public Holidays.
I need to link those tables with employee assignments. 

PER_SCHEDULE_ASSIGNMENTS
PER_SCHEDULE_EXCEPTIONS

​Please help me