R K Ranjan
"High speed forging of solid powder polygonal discs with bulging".
Tamkang J. of Sci. and Engineering, Taiwan, ROC,
vol: 7,
No. 3
Jan. 2004,
pp: 219-226,
https://scholar9.com/publication-detail/high-speed-forging-of-solid-powder-polygonal-discs-5232