Yamada, S., Y. Tokushige, T. Tanaka, and T. Tanino. “AN OUTER APPROXIMATION METHOD UTILIZING THE RELATION OF CONNECTIONS AMONG VERTICES FOR SOLVING A DC PROGRAMMING PROBLEM”. Journal of Nonlinear Analysis and Optimization: Theory & Applications 3, no. 1 (March 31, 2012): 1-12. Accessed September 21, 2021. http://www.math.sci.nu.ac.th/ojs302/index.php/jnao/article/view/71.