1977-08-31 /AP-4172F-BM/01/3a-sources/conv20.ctl 1977-08-31 /BB-H138A-BM/01/3a-sources/conv20.ctl 1977-08-31 /bb-d868a-bm/01/3-sources/conv20.ctl 1977-08-31 /bb-d868b-bm_tops20_v3a_2020_dist/01/3a-sources/conv20.ctl