Das, P., and E. Savaş. “On Generalized Statistical and Ideal Convergence of Metric-Valued Sequences”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 68, no. 12, Dec. 2016, pp. 1598-06, https://umj.imath.kiev.ua/index.php/umj/article/view/1946.