วรุณโรจน์ จ. . A study of the thickness on the natural frequency in the free vibration of clamped - clamped steel plate. Frontiers in Engineering Innovation Research, [S. l.], v. 1, p. 61–67, 2013. Disponível em: https://ph01.tci-thaijo.org/index.php/jermutt/article/view/242092. Acesso em: 11 dec. 2025.