Huda, nurainul, and Nurfitri Imroah. 2021. “Analysis of the Changes in 2019-NCov Before and After the Implementation of the "Required Swab PCR-Test for Entry into West Kalimantan via Air Transport" Policy”. Tensor: Pure and Applied Mathematics Journal 2 (1), 33-44. https://doi.org/10.30598/tensorvol2iss1pp33-44.