C. Ludwig, J. Knippers, E. Hugi, and K. Wakili. Fourth International Conference on FRP Composites in Civil Engineering (CICE2008), Zürich, (22-24 July 2008)
J. Knippers, M. Oppe, and F. Waimer. Stahlbau-Kalender 2015: Schwerpunkte: Eurocode 3 - Grundnorm, Leichtbau, page 463 – 516. Ernst & Sohn, Berlin, (2015)
C. Ludwig, J. Knippers, E. Hugi, and K. Wakili. The Fifth Middle East Symposium on Structural Composites for Infrastructure Applications – Extend Abstract, page 136 – 137. Cairo, The Egyptian Society of Engineers, (2008)