International trade statistics :    concepts and definitions. 

 - New York :    United Nations,    1970. 
 - iii, 68 p.  ;    28 cm. 
 - Statistical papers.    Series M ;    no. 52 .
<br/><br/>Includes bibliographical references. 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Commercial statistics.