Askin, Hakan, et al. “Simultaneous Determination of α-Amyrin and β-Sitosterol in Centranthus Longiflorus Stev. Subsp. Longiflorus Stev and Iris Taochia Woronow Ex Grossh by GC-MS Method”. Progress in Nutrition, vol. 20, no. 1-S, Aug. 2018, pp. 209-17, https://doi.org/10.23751/pn.v20i1-S.6744.