Gikas E, Bazoti FN, Papadopoulos N, Alesta A, Economou G, Tsarbopoulos A. Quantitation of the Flavonols Quercetin and Kaempferol in the Leaves of Trigonella foenum-graecum by High-Performance Liquid Chromatography–Diode Array Detection. Analytical letters. 2011;44(8):1463-1472.