contact de Hertz
1985 / Collision between two balls accompanied by deformation: A qualitative approach to Hertz's theory / Bernard Leroy / American Journal of Physics 53 (1985) p. 346 [doi]
2000 / Inelastic collision and the Hertz theory of impact / D. Gugan / American Journal of Physics 68 (2000) p. 920 [doi]
2003 / Contact et impact de sphères / Basile Audoly ; Yves Pomeau / Dossier Pour la Science 41 (2003) p. 6