Abstracts of contributed papers 

 - [Tucson ] :  [University of Arizona],  [s. a.] 
 - s. p. 
<br/><br/><label>LCCN: </label>25827 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Regiones áridas--Congresos.
<br/><br/><label>Dewey Class. No.: </label>631.0915  / I57 1969