@misc{petersen_deposition_of_1989, 
author={Petersen, G.},
title={Deposition of heavy metals to the North Sea and the Baltic Sea},
year={1989},
howpublished = {conference lecture: Oslo (N); 07.03.1989},
note = {Online available at: \url{} (DOI). Petersen, G.: Deposition of heavy metals to the North Sea and the Baltic Sea. Kolloquium des Norwegischen Meteorologischen Instituts. Oslo (N), 1989.}}