1973. Letter of invitation from Demarco to Hans Hollein. The Austrian Exhibition. Edinburgh Arts 1973.
1981. Architect Hans Hollein, left, in his newly completed Staditsche Museum, Monchengladbach. Johannes Cladders, Director of Stadtische Museum, Monchengladbach, right.
1973. Exhibition Catalogue. Page 11/25. Hans Hollein. The Austrian Exhibition. RDG, Edinburgh, and Institute of Contemporary Arts, London.