1981-12-11 /BB-4157E-BM/01/fortran-system/20sys.dir 1982-01-29 /ALGOL-20_1-29-82/01/algol-system/20sys.dir 1982-01-29 /ALGOL-20_29Jan82/01/algol-system/20sys.dir 1982-01-29 /BB-5471C-BM_1982/01/algol-system/20sys.dir 1983-02-09 /BB-4157F-BM_1983/01/fortran/system/20sys.dir