Hoang Anh, N. T.; Tuan, N. V.; Quan, T. D.; Thien, D. D.; Tam, N. T.; Thuy, T. T.; Sung, T. V. Chemical Constituents of Chirita Drakei Burtt Collected in Ha Long Bay, Quang Ninh Province, Viet Nam. Part 2. Compounds Isolated from the N-Butanol Extract. VJChem 2017, 55, 504.