00274 a2200121 4500 63109 004 WAL 37276 37276 Walker, Roger S Understanding Computer Science English Radio Shack 1981 200p CAE NUST 004 WAL 298182 298182 0 0 0 0 NFIC CAE CAE 2017-04-03 0 004 WAL CAEG-5624 2017-04-05 2017-04-05 BK