@misc{guenther_the_wam_1992, 
author={Guenther, H., Hasselmann, S., Janssen, P.A.E.M.},
title={The WAM model cycle 4.0 user manual},
year={1992},
howpublished = {report},
note = {Guenther, H.; Hasselmann, S.; Janssen, P.: The WAM model cycle 4.0 user manual. 1992.}}