”Heidi Guthmann Birck – Aage Birck, Skulptur og Unika“ catalogue with

preface by  Lise Funder, director of Udstilligsbygningen Nikolaj

Copenhagen,and Dr. Eckard Wagner, director of Emslandmuseum

 Schloss Clemenswerth, Sögel, Germany,

ISBN: 87-98183-73 Multi Mud – 1988.