@misc{hempel_behaviour_of_1991, 
author={Hempel, M.},
title={Behaviour of mercury compounds in soils},
year={1991},
howpublished = {conference lecture: Burlington (CDN); 15.-18.04.1991},
note = {Online available at: \url{} (DOI). Hempel, M.: Behaviour of mercury compounds in soils. Workshop on Biological Interactions of Metals and Organometals in the Environment. Burlington (CDN), 1991.}}