004330000a22001210004500060000800000082001500008100002000023245013900043260004100182260000900223300000800232650007100240  a100  a658.83 HAR  aHarder, Theodor  aIntroduction to mathematical models in market and opinion research : with practical application, computing procedures and estimates of  aHolland, D.Reidel publishing company  c1969  a194  aAdversting media calculations/ mathematical models - market models