1. Contact and Rubbing of Flat Surfaces
2. E. Rabinowicz, Friction and Wear of Materials (John Wiley & Sons, Inc., 1995).
3. I. V. Kragelski, Friction and Wear (Butter Worth, 1965).
4. http://www.pressestelle.tu-berlin.de/menue/tub_medien/publikationen/medieninformationen/2017/oktober_2017/medieninformation_nr_1692017/
5. The effect of size on the looseness of wear fragments