@misc{michaelis_seminar_ueber_1991, 
author={Michaelis, W.},
title={Seminar ueber Umweltphysik},
year={1991},
howpublished = {lecture: Universitaet Hamburg; 1991},
note = {Online available at: \url{} (DOI). Michaelis, W.: Seminar ueber Umweltphysik. Universitaet Hamburg, 1991.}}