@misc{schwalbe_elasticplastic_fracture_1991, 
author={Schwalbe, K.-H.},
title={Elastic-plastic fracture mechanics test method EGF P1-90 on the background of other existing methods},
year={1991},
howpublished = {conference lecture (invited): Lissabon (P); October 1-2, 1991},
note = {Online available at: \url{} (DOI). Schwalbe, K.: Elastic-plastic fracture mechanics test method EGF P1-90 on the background of other existing methods. 4th Portuguese Conference on Fracture. Lissabon (P), 1991.}}