@misc{heerens_modifications_of_1988, 
author={Heerens, J., Schwalbe, K.-H., Cornec, A.},
title={Modifications of ASTM E 813-81 standard test method for an improved definition of Jic using new blunting-line equation},
year={1988},
howpublished = {GKSS report},
note = {Heerens, J.; Schwalbe, K.; Cornec, A.: Modifications of ASTM E 813-81 standard test method for an improved definition of Jic using new blunting-line equation. In: Read, D.; Reed, R. (Ed.): Fracture Mechanics: Eighteenth Symposium - ASTM STP. Philadelphia: ASTM. 1988. 374-389.}}