Popov, Valentin L., et al. “A Simple Approximation for Indentation of Finite Elastic Layers by Parabolic, Conical, and Flat-Ended Cylindrical Indenters”. Spectrum of Mechanical Engineering and Operational Research, vol. 3, no. 1, Mar. 2026, pp. 18-27, https://doi.org/10.31181/smeor202650.