000			003940000a22001690004500
245			_aHow to use adding and calculating machines
100			_aWalker, Arthur L.
250			_a4th
260			_aNew Yorj _bMcGraw-Hill _c1979
300			_a218 p.
020			_a0-07-067825-1
080			_a681.31 _bW3
650			_aCOMPUTERS-ADDERS
650			_aCALCULATORS
041			_aEN
942			_cBK
999			_c60082 _d60082