Vinh, P.C. and Anh, V.T.N. 2015. An approximate secular equation of Rayleigh waves in an elastic half-space coated by a thin weakly inhomogeneous elastic layer. Vietnam Journal of Mechanics. 37, 1 (Feb. 2015), 71–80. DOI:https://doi.org/10.15625/0866-7136/37/1/5900.