TY  - BOOK
AU  - Walker,Arthur L.
AU  - Roach,J.Kenneth
AU  - Hanna,J.Marshall
TI  - How to use adding and calculating machines: full-keyboard adding machine, ten-key adding machine, printing calculator, rotary calculator, key-driven calculator 
SN  - 070678235
PY  - 1967///]
CY  - New York
PB  - Gregg Division, McGraw-Hill
KW  - Calculators
KW  - Problems, exercises
ER  -