1. S. Kalpakjian, S.R. Schmid, Manufacturing Processes for Engineering Materials (Pearson, Up Saddle River, 2007)
2. S.R. Schmid, W.R.D. Wilson, in Modern Tribology Handbook (CRC, New York, 2000)
3. D. Tabor, The Hardness of Metals (Oxford University Press, Oxford, 1951)
4. W. Johnson, R. Sowerby, R. Venter, Plane Strain Slip Line Fields for Metal Deformation Process Source Book & Bibliography (Pergamon, Oxford, 1982)
5. V.E. Lysaght, Indentation Hardness Testing (Reinhold, New York, 1949)