TY  - BOOK
AU  - Lankford,Francis Greenfield,1906-
AU  - Heikkinen, Donald D.
AU  - Silvey, Ina M.
TI  - Numbers and operations
PY  - 1970///
CY  - New York
PB  - Harcourt
KW  -  Numeration
KW  -  Mathematics
ER  -