E Herawati, and S N R Gultom. “On Certain Type of Sequence Spaces Defined by 𝝋 − Function ”. Journal of Research in Mathematics Trends and Technology 1, no. 2 (September 30, 2019): 61-67. Accessed December 5, 2024. https://talenta.usu.ac.id/jormtt/article/view/2838.