Motivation:   Theory , Research and Applications / 
Petri Herbert L. 
 - 3rd ed. 
 - California :  Wadworth Pub Co. ,  1991. 
 - xiv,434 p,:  ill,; 
<br/><br/><label>ISBN: </label>0534143644 
<br/><br/><label>LC Class. No.: </label>BF503  / .P47  1991