TY  - BOOK
AU  - Hales,Richard
AU  - 
TI  - Adding
T2  - Learning tree 1 2 3
SN  - 1855344521
U1  - 511 23
PY  - 1991///
CY  - New Lanark, ML : 
PB  - Geddes and Grosset , 
KW  - Mathematics
ER  -