@misc{schafstall_state_of_1989, 
author={Schafstall, H.-G.},
title={State of the art in underwater technology},
year={1989},
howpublished = {conference lecture: Goeteborg (S); October 31, 1989},
note = {Online available at: \url{} (DOI). Schafstall, H.: State of the art in underwater technology. Colloquium of the Chalmers University of Technology. Goeteborg (S), 1989.}}