TY  - BOOK
AU  - Giet, A.French.
AU  - Head, J.W.
AU  - Phippen, H.D.
TI  - Abacs or nomograms: An introduction to their theory and constructions
U1  - 604.2 
PY  - 1956///
CY  - London
PB  - Illfe and Sons Ltd.
ER  -