00333nam a2200109Ia 4500008004100000040003800041100001500079245003700094260005000131300001500181653002700196211228s9999    xx            000 0 und d  cJayakar Knowledge Resource Centre  aUllman,E L 0aGeography as spatial interaction  bUniversity of Washington pressaSeattlec1980  axix,231 p.  aAnthropology-Geography