S.Alansari, L., M.HAl-Hajjar, A. and Jawad A., H. (2019) “Calculating the natural frequency of cantilever tapered beam using classical Rayleigh, modified Rayleigh and finite element methods”, International Journal of Engineering & Technology, 7(4), pp. 4866–4872. doi:10.14419/ijet.v7i4.25334.