00306nam a2200109Ia 4500082002600000100002400026245007300050260004800123300001500171500000500186700000500191  a309.51509492bH758.OM  aHoltgrefe, A. A. I.  aOptimizing medium term planning model for the Netherlands railwaysb  aRotterdambRotterdam University Pressc1975  axiv, 164p.  a  a