Technology, Human activity systems: A systems approach 

 - Milton Keynes  OPen University Press  1975 
 - 47p. 
<br/><br/><label>ISBN: </label> UKP 1.95 
<br/><br/><label>Source: </label> UKP 1.95 
<br/><br/><label>Dewey Class. No.: </label>600 TEC