El desafio ecológico / 
Lewis Mumford ... [et al.]. 
 - Caracas :  El Cid Editor,  1977 
 - 152 p. 
 - Cuadernos del CN ;  8 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ecology.<br/>Pollution--Environmental aspects.
<br/><br/><label>LC Class. No.: </label>QH 541  / D441 1977