Sen, M., and P. Debnath. “BEST APPROXIMATION IN INTUITIONISTIC FUZZY N-NORMED LINEAR SPACES”. Journal of Nonlinear Analysis and Optimization: Theory & Applications 3, no. 1 (March 31, 2012): 45-53. Accessed September 21, 2021. http://www.math.sci.nu.ac.th/ojs302/index.php/jnao/article/view/103.