Ngoc Huyen, D.; Thi Tuyen, P.; Thi Loan, V.; Xuan Dac, L. THE CONTENTS OF 20-HYDROXYECDYSONE (20E), QUERCETIN AND ESSENTIAL OILS IN ASTERACEAE SPECIES GROWING IN TAM DAO DISTRICT, VINH PHUC PROVINCE, VIETNAM. J. Forest. Sci. Technol. 2019, 072-081.