T. Kim Qui, T. Hoang, N. Thuy Nhi, and N. Thi Ngoc, “A NOVEL EXTRACTION METHOD OF VINDOLINE AND CATHARANTHINE FROM THE CATHARANTHUS ROSEUS G.DON (APOCYNACEAE)”, VNUHCM Journal of Science and Technology Development, vol. 1, no. 5, pp. 29-33, May 1998.