1H and 13C NMR assignments of new ecdysteroids from Callisia fragrans. (8th April 2015) - Hang, Dan Thi Thuy; Hang, Nguyen Thi Minh; Anh, Hoang Le Tuan; Nhiem, Nguyen Xuan; Hue, Cao Thi; Binh, Pham Thanh; Dat, Nguyen Tien; Nam, Nguyen Hoai; Yen, Pham Hai; Minh, Chau Van; Hung, Nguyen Van; Kiem, Phan Van