1. de Boer J (1984) Ph.D thesis, University of Groningen, The Netherlands
2. Dumbleton J H (1981) Tribology of natural and artificial joints. Elsevier, North-Holland Amsterdam
3. Cooper J R (1993) Wear 162–164:378
4. Gunther J S B, Rose R M (1994) J. Long-term Eff. Medical Impl. 4:157
5. Wang A, Sun D C, Stark C, Dumbleton J H (1995) Wear 181–183:241