Relaxant Effects of Quercetin Methyl Ether Derivatives in Isolated Guinea Pig Trachea and their Structure-Activity Relationships - Ko, Wun-Chang; Kuo, Shih-Wu; Sheu, Joen-Rong; Lin, Chien-Huang; Tzeng, Shu-Huey; Chen, Chi-Ming (Planta Medica, 1999)