E Herawati, and S. N. R. Gultom. β€œOn Certain Type of Sequence Spaces Defined by 𝝋 βˆ’ Function ”. Journal of Research in Mathematics Trends and Technology, vol. 1, no. 2, Sept. 2019, pp. 61-67, doi:10.32734/jormtt.v1i2.2838.