Validation of a HPLC-tandem MS/MS method for pharmacokinetics study of (+)-pinoresinol-di-β-d-glucopyranoside from Eucommia ulmoides Oliv extract in rats’ plasma - Wang, Jia-Long; Liu, Er-Wei; Zhang, Yi; Wang, Tao; Han, Li-feng; Gao, Xiu-Mei (Journal of Ethnopharmacology, 2012)