TY  - BOOK
AU  - Held, Wolfgang
TI  - The quality of numbers 1 to 31
SN  - 9780863158643
U1  - CIR 513 H474 2012 
PY  - 2012///
CY  - Edinburgh
PB  - Floris Books
KW  - Arithmetic
KW  - Study and teaching
N1  - Includes bibliography
ER  -