KLECHA, T. Surface stress waves in a nonhomogeneous elastic half-space. Part II. Existence of surface waves for an arbitrary variation of Poisson’s ratio. Approximate solution based on perturbation methods. Archives of Mechanics, Warsaw, Poland, v. 48, n. 3, p. 513–539, 1996. DOI: 10.24423/aom.1354. Disponível em: http://am.ippt.gov.pl/index.php/am/article/view/v48p513. Acesso em: 17 jan. 2026.