Aspects of educational technology EDIT / 
editor John Leedham. 
 - Bath:   Pitman,   Association for Programmed Learning and Educational Technology  1975.  
 - 309 p. ;  24 cm. 
<br/><br/><label>ISBN: </label>0273317830 0273317822 0273361325 0273314106 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Educational technology