The measurement of development effort;    study. 

 - New York :    United Nations,    1970. 
 - vii, 64 p.;    23 cm. 
<br/><br/>  "United Nations publication. Sales number: E.71.II.D.4." 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>Subjects--Geographic Terms: </label><br/> Developing countries -- Economic conditions.