TY  - BOOK
AU  - Cotsworth, M. B. 
TI  - Cotsworth's direct calculator : containing over 1,000,000 distinct calculations for expediting and ensuring accuracy in multiplication, division, average, percentage, interest, exchange and general calculation by all combinations of numbers from 1 to 1000 ..
PY  - 1896///
CY  - London
PB  - M. B. Cotsworth
KW  - Calculator
ER  -