TY  - BOOK
AU  - Hartree,Douglas R.
TI  - Calculating instruments and machines
U1  - 510.78 HAR  
PY  - 1950///.
CY  - Cambridge : 
PB  - At the university press, 
KW  - Computer- History
KW  - Differential analyser
N1  - Includes subject index.
ER  -