Nguyen Thi Thanh Tu, Vu Dinh Minh, Nguyen Thanh Tung, and Nguyen Minh Quy. “RESEARCHING AND BUILDING AN OPEN SOURCE ANTI-SPAM (SPAM-AVOIDANCE) FRAMEWORK FOR UNIVERSITY’S EMAIL SYSTEM”. UTEHY Journal of Science and Technology, Vol. 12, Jan. 2017, pp. 83-88, http://tapchi.utehy.edu.vn/index.php/jst/article/view/238.