Time and frequency analysis of vostok ice core climate data. Periodicals of Engineering and Natural Sciences, [S. l.], v. 7, n. 2, 2026. DOI: 10.21533/pen.v7.i2.1600. Disponível em: https://pen.ius.edu.ba/index.php/pen/article/view/1600. Acesso em: 11 sep. 2026.