Yayuk Wahyuni, Mohammad Imam Utoyo, and Slamin. “ilangan ominasi raf asil perasi orona isi”. imits: ournal of athematics and ts pplications, vol. 16, no. 2, Dec. 2019, pp. 135-46, https://journal.its.ac.id/index.php/limits/article/view/5426.