@misc{doerffer_estimation_of_1993, 
author={Doerffer, R.},
title={Estimation of primary production by observation of solar-stimulated fluorescence},
year={1993},
howpublished = {journal article,GKSS report},
note = {Online available at: \url{} (DOI). Doerffer, R.: Estimation of primary production by observation of solar-stimulated fluorescence. ICES Marine Science Symposia. 1993. vol. 197, 1-10.}}