Page 29 - Studio Interantional - May 1967
        P. 29
     Works of the 1930s—top left, an ink study of 1939; bottom left,  Etude
         1935; top right,  Zebra, an ink drawing of 1936; bottom right,  Harlequin
         of 1935
          Of this period Vasarely has written : 'It was in my Two-dimensional
         graphic studies executed between 1933 and 1938 that Optical
         Kineticism finally appeared in a vigorous and decisive way.
         Checkerboards, Harlequins, Zebras, Tigers, Prisoners and Martians
         moved, not by mimetism but by the aggressiveness with which their
         structures struck the retina.'
     	
