Quantitative determination of biologically active constituents in crude extracts of medicinal plants by thin-layer chromatography-densitometry. II. Eleutherococcus senticosus Maxim., Panax ginseng Meyer and Picrorrhiza kurroa Royle
J Chromatogr. 1984 Nov 16:312:497-503.
doi: 10.1016/s0021-9673(01)92806-7.