Cavalini, A.A., V.R. Franco, C.G. Gonsalez, V. Lopes Jr., and G.P de Melo. 2008. “Noise Influence on Damage Detection through Modal State Observers Methodology”. Trends in Computational and Applied Mathematics 9 (2):195-204. https://doi.org/10.5540/tema.2008.09.02.0195.