United nations <br/><br/>
Long-term planning of water management.   proceedings of the Seminar on Long-Term Planning of Water Management, Zlatni Piasatzi, Bulgaria, 17-22 May 1976. 
United nations 
 - New York,    United Nations  1976 
 - 3Vols   28 cm. 
<br/><br/>  At head of title: Economic Commission for Europe.  "United Nations publication. Sales no. E.76.II.E.27." 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Water resources development --Congresses
<br/><br/><label>Dewey Class. No.: </label>333.91  / UNI