You may also wish to search for items by Ludwig-Koehn.
Only one matching reference was found.
Ludwig-Koehn, H.; Henning, H.V., Some aspects of quantification of neutral steroid metabolites in body fluids of healthy and uremic subjects by capillary gas chromatography, J. Hi. Res. Chromatogr. Chromatogr. Comm., 1986, 9, 1, 35-38, https://doi.org/10.1002/jhrc.1240090106 . [all data]