@misc{stockdreher_a_study_1989, 
author={Stockdreher, E., Behrens, A., Koch, W., Ziemer, F.},
title={A study on ship route optimization: measurement and simulations},
year={1989},
howpublished = {GKSS report},
note = {Stockdreher, E.; Behrens, A.; Koch, W.; Ziemer, F.: A study on ship route optimization: measurement and simulations. In: Blake, M. (Ed.): CAMS '89: IFAC Workshop on Expert Systems and Signal Processing in Marine Automation. Lyngby (DK). 1989. 247-258.}}