Fratzl, P. Peter Fratzl, Biomaterialien, Max Planck Institute of Colloids and Interfaces, Max Planck Society;
Kienzler, R., Fischer, F. D., & Fratzl, P. (2006). On energy changes due to the formation of a circular hole in an elastic plate. Archive of Applied Mechanics, 76(11-12), 681-697. doi: 10.1007/s00419-006-0048-2.