00342pab a2200121 454500008004000000100002000040245006300060260000900123300001200132362000900144650002900153773003800182180718b1983   xxu||||| |||| 00| 0 eng d  aWalker, Jack L.  aThe origins and mainstenance of interest groups in America  c1983  a390-406  aJune  aPressure Groups - U.S.A.  aAmerican Political Science Review