= Cat. no.550. The 3 photographs each show a "Circle made by throwing a stone of equal weight as sheet".

AND 2 others by the same: The longest night in Venice (Biennale 1982) and an untitled publication w. 3 plates showing horizontal and vertical lines (Haarlem, Frans Hals Mus., 1974). - ADDED: 4 works by/ on SIGURDUR GUDMUNDSSON, i.a. The Ten Commandments/ Joining The Ten Commandments (2 vols. w. diff. title but identical contents, Haarlem, Frans Hals Mus., 1974).