TY  - BOOK
AU  - Lipsey, Richard G.
AU  - Forrest, David./ Olsen, Wendy.
TI  - Workbook for the Seventh Edition of An Introduction to positive Economics
SN  - 0297795570
AV  - HB171.5Z5lip. 
PY  - 1989///
CY  - London.
PB  - Weidenfeld and Nicolson.
ER  -