Instructional technology :  foundations / 
edited by Robert M. Gagne'. 
 - 1986  ed. 
 - New York :  Routledge,  1986. 
 - viii, 473  p. 
<br/><br/><label>ISBN: </label>0898598788 : 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Educational technology.<br/>Instructional systems.