Jurnal Ilmiah Sains, [S. l.], v. 11, n. 2, p. 191–197, 2011. DOI: 10.35799/jis.11.2.2011.206. Disponível em: https://ejournal.unsrat.ac.id/v3/index.php/JIS/article/view/206. Acesso em: 17 mei. 2024.