Blackburn, David A <br/><br/>
Distance learning for technical and vocational education at pre-university level establishments of open tech type / 
David A. Blackburn;R. C. Smith. 
 - Paris :  UNESCO,  1987. 
 - 52 p. 
 - Studies in technical and vocational education ;  27. .
<br/><br/><label>No. de Clasificación Universal Decimal: </label>374.1 (410) =20 BLA No.27.