Ekman, Paul <br/><br/>
Unmasking the face :  a guide to recognizing emotions from facial clues / 
Paul Ekman and Wallace V. Friesen 
 - Englewood Cliffs, N. J. :  Prentice-Hall,  1975 
 - 212 p. :  ill. ;  23 cm. 
 - A spectrum book .
<br/><br/><label>ISBN: </label>013938183X 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Facial expression