Ullman Edward L <br/><br/>
Geography as spatial interaction Ed by Ronal R Bo 
Ullman Edward L 
 - Washington  University of Washington Press         1980 
 - xix,231p. Bib p. 223-26  cm. 
<br/><br/><label>ISBN: </label>0295957115 
<br/><br/><label>Source: </label> General Book 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geography
<br/><br/><label>Dewey Class. No.: </label>U, M0