Peramalan Harga Batubara Acuan Menggunakan Metode PSOSVR dan IPSOSVR. Jurnal EurekaMatika, [S. l.], v. 9, n. 1, p. 69–94, 2021. Disponível em: https://ejournal-science.upi.edu/jem/article/view/226. Acesso em: 1 jul. 2026.