@misc{heerens_thickness_contraction_2001, 
author={Heerens, J.,Hellmann, D.},
title={Thickness Contraction and Ligament Contraction - Two Quantities to Analyse constraint Effects on Ductile Fracture Toughness},
year={2001},
howpublished = {book part},
note = {Online available at: \url{} (DOI). Heerens, J.; Hellmann, D.: Thickness Contraction and Ligament Contraction - Two Quantities to Analyse constraint Effects on Ductile Fracture Toughness. In: Kocak, M. (Ed.): The Life of a Crack, Initiation - Growth - Fracture, Manuscript 9. Geesthacht: GKSS-Forschungszentrum. 2001.}}