TY  - BOOK
AU  -  Mold,Josephine
TI  -  Counting machines / 
SN  -  0521203791
U1  -  513.2 
PY  - 1974///
CY  -  Cambridge : 
PB  -  Cambridge University Press, 
KW  -  Numeration
KW  -  Juvenile literature
KW  -  Mathematics
KW  -  Number systems
ER  -