; ; . Jurnal Ilmiah Sains, [S. l.], v. 11, n. 2, p. 248–252, 2011. DOI: 10.35799/jis.11.2.2011.215. Disponível em: https://ejournal.unsrat.ac.id/v3/index.php/JIS/article/view/215. Acesso em: 18 jul. 2024.