Staande figuur binnen ellips

Anton Heyboer, ca. 1960, prent, RP-P-2010-222-2252

Het systeem

Anton Heyboer, 1957 - 1968, prent, RP-P-2011-121-17

Blad 3

Anton Heyboer, 1962, prent, RP-P-2010-221-1935-16

Blad 15

Anton Heyboer, 1962, prent, RP-P-2010-221-1935-6

Blad 16

Anton Heyboer, 1962, prent, RP-P-2010-221-1935-3

Blad 13

Anton Heyboer, 1962, prent, RP-P-2010-221-1935-7

Blad 1

Anton Heyboer, 1962, prent, RP-P-2010-221-1935-22

Blad 16

Anton Heyboer, 1962, prent, RP-P-2010-221-1935-4