A Meta-analysis of rates of return to agricultural R & D  : ex pede Herculem? 
Julian M. Alston...[et al.] 
 - Washington  IFPRI  2000 
 - x, 148 p.  26 cm 
 - Research report / IFPRI  113 .
 - Research report / IFPRI .
<br/><br/><label>ISBN: </label>0896291162 
<br/><br/><label>Subjects--Index Terms: </label>Analisis economico Analisis de costos y beneficios Rentabilidad Investigacion