“National Payment Gateway (GPN) As an Instrument in Optimizing Income Tax Withdrawal on E-Commerce Transactions”. Jurnal Ilmu Hukum Kyadiren 1, no. 2 (January 30, 2020): 90–106. Accessed August 7, 2025. https://journal.stihbiak.ac.id/index.php/kyadiren/article/view/124.