@misc{heerens_delta_5_2001, 
author={Heerens, J.,Schoedel, M.,Hellmann, D.},
title={Delta 5 and CTOA - Experimental and Numerical Observations},
year={2001},
howpublished = {conference lecture: Geesthacht (D); 23.-26.04.2001},
note = {Online available at: \url{} (DOI). Heerens, J.; Schoedel, M.; Hellmann, D.: Delta 5 and CTOA - Experimental and Numerical Observations. Workshop on the Fundamentals and Applications of the Crack Tip Opening Angle (CTOA). Geesthacht (D), 2001.}}