@article{article,
title = {Comparison of various reversed-phase columns for the simultaneous determination of ephedrines in urine by high-performance liquid chromatography},
author = {},
year = {2000},
journal = {Journal of Chromatography A},
volume = {870},
number = {1-2},
pages = {23-28},
howpublished = "\url{https://eurekamag.com/research/010/364/010364243.php}"
}