(Contributed papers) 

 - (s.l. :  s.e.),  (s.a.) 
 - 3 v.  : ilus 
<br/><br/><label>LCCN: </label>25829 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Regiones áridas--Congresos.
<br/><br/><label>Dewey Class. No.: </label>631.0915  / I5 1969