APPROXIMATE METHOD FOR THE DETERMINATION OF NATURAL FREQUENCIES OF A MULTI-DEGREE OF FREEDOM BEAM SYSTEM. Nigerian Journal of Technology, [S. l.], v. 30, n. 2, p. 1–6, 2009. DOI: 10.4314/njt.302.45. Disponível em: https://nijotech.com/index.php/nijotech/article/view/45. Acesso em: 19 apr. 2026.