T. . Trzepieciński, Łukasz . Bąk, F. . Stachowicz, S. . Bosiakov, and S. . Rogosin, “ANALYSIS OF CONTACT OF A RIGID SPHERE AGAINST A DEFORMABLE FLAT”, Acta Metall Slovaca, vol. 21, no. 4, pp. 285–292, Dec. 2015.