"Inverse Hanging Membrane: The Naturtheater Grötzingen" by Tessa Maurer, Elizabeth O'Grady, Ellen Tung, Evolution of German Shells Forms: Efficiency of Form, Princeton University Dept. Civil and Environmental Engineering."

“Heinz Isler: A few important things by Build LLC., Architects|Designers.”

“Heinz Isler: Shells for Two Churches" by, Journal of the International Association for Shell and Spatial Structures Vol. 52, No.3 September n. 169.”

“heoretical considerations and derivations … are always based on severe simplifications of the assumptions.”

“Among others there are three methods for shaping shells: the freely shaped hill, the membrane under pressure and the hanging cloth reversed.”

“...I do not say any form which you construct this way is a good form, or must lead to a good solution; but there are forms which can lead to good solutions, and of course that is only the first link in a whole chain of investigations, and the other links in the investigation, model tests, measuring of the first structure, or a model test in scale 1:1 as we have it out here, these are of primary importance. So the engineer problem is remaining all the same, but it is the first link, here, the shaping which has been lacking up to now, and this method can lead to a very nice solution.”

“The Architecture of Heinz Isler by Toni Kotnik, Joseph Schwartz, Journal of the International Association for Shell and Spatial Structures Vol. 52, No. 3, 'Special Issue: Heinz Isler - 50 Years of "New Shapes for Shells"' Guest editors: J. F. Abel, J. C. Chilton.”