• Willert E. Adhesive tangential impact without slip of a rigid sphere and a power-law graded elastic half-space: Numerical analysis based on the Method of Dimensionality Reduction / E. Willert, V. L. Popov // ZAMM : Zeitschrift für angewandte Mathematik und Mechanik. 2017. Vol. 97, № 7. P. 872-878. URL: http://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000620620