Amir, Mohammad Faizal, and Bayu Hari Prasojo. “Buku Ajar Matematika Dasar”. Umsida Press (August 22, 2021): 1=197. Accessed December 16, 2024. https://press.umsida.ac.id/index.php/umsidapress/article/view/978-979-3401-66-9.