DehghanN. A. and MazaheriH. (2010) “New results in $G$-best approximation in $G$-metric spaces”, Ukrains’kyi Matematychnyi Zhurnal, 62(4), pp. 567–571. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/2888 (Accessed: 22July2024).