00314n   a2200121 a 4500000002100000001000700021005001700028082001600045245007100061260002600132300001200158700002200170B B                 00653420220201171700.0  a330bM9 ECO  aWork Book for the seventh of an introduciton to Positive Economics  aLondonbE L B Sc1989  av,313p.  aLipsey, Richard G