1. P. Brissonneau, Magnétisme et matériaux magnétiques pour l’électrotechnique, Hermes, 1997, pp. 236–239.
2. Schuler, Metal Forming Handbook, Springer, Berlin, 1998, pp. 296–310 (Chapter 4).
3. R. Pearce, Sheet Metal Forming, The Adam Hilger Series on New Manufacturing Processes and Materials, 1991.
4. G.E. Dieter, Mechanical Metallurgy, SI Metric Edition, 1988, p. 657.
5. H.E. Theis (Ed.), Handbook of Metalforming Processes, 1999, pp. 2333–239 (Chapter 9).