00294nam a2200109Ia 4500082001800000100002000018245008300038300001400121490001400135490003000149500000500179  a330.183 Z51b  aZellner, Arnold  aThree stage least squares; simultaneous estimation of simultaneous equationsb  app. 54-78  vJan. 1962  aEconometrica, v.30, no.1   a