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References
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.. _ref-1:

[1] E. Hairer, C. Lubich, and G. Wanner. Geometric Numerical Integration, volume 31 of Springer Series in Computational Mathematics. Springer-Verlag, Berlin, 2001.



.. _ref-2:

[2]	Claude Lacoursiére. Ghosts and Machines: Regularized Variational Methods for Interactive Simulations of Multibodies with Dry Frictional Contacts. PhD thesis, Dept. of Computing Science, Umea University, June 2007.



.. _ref-3:

[3] K L Johnson. Contact Mechanics. 1985. doi: 10.1115/1.3261297. url:  https://www.amazon.fr/Contact-Mechanics-K-L-Johnson/dp/0521347963.



.. _ref-4:

[4]	AntonioPérez-González et al. "A modified elastic foundation contact model for application in 3D models of the prosthetic knee". In: Medical Engineering & Physics 30.3 (2008), pp. 387–398. issn: 13504533. doi: 10.1016/j. medengphy.2007.04.001. url: http://linkinghub.elsevier.com/retrieve/pii/S1350453307000616.