@misc{boeddeker_sample_preparation_1990, 
author={Boeddeker, H.},
title={Sample preparation methods for TXRF-analysis of blood, blood serum and urine},
year={1990},
howpublished = {conference lecture: Vienna (A); 15.-17.05.1990},
note = {Online available at: \url{} (DOI). Boeddeker, H.: Sample preparation methods for TXRF-analysis of blood, blood serum and urine. 3rd Workshop TRFA. Vienna (A), 1990.}}