@misc{markert_multielement_analysis_1989, 
author={Markert, B.},
title={Multi-element analysis in ecosystems: Basic conditions for representative sampling of plant materials},
year={1989},
howpublished = {journal article},
note = {Online available at: \url{} (DOI). Markert, B.: Multi-element analysis in ecosystems: Basic conditions for representative sampling of plant materials. Fresenius Journal of Analytical Chemistry. 1989. vol. 335, 562-565.}}