E. Bagherpour, M. Reihanian, N. Pardis, R. Ebrahimi, Ten years of severe plastic deformation (SPD) in Iran, part I: Equal-channel angular pressing (ECAP), Iranian Journal of Materials forming, 5(1) (2018), 71-113.
 E. Bagherpour, N. Pardis, M. Reihanian, and R. Ebrahimi, An overview on severe plastic deformation: research status, techniques classification, microstructure evolution, and applications, The International Journal of Advanced Manufacturing Technology, (2019), 1647-1694.
 M. Nouri, H. Mohammadian Semnani, E. Emadoddin, H.S. Kim, Investigation of direct extrusion channel effects on twist extrusion using experimental and finite element analysis, Measurement., (2018), 115-123.
 R.Z. Valiev, A. V. Korznikov, A. V., R. R. Mulyukov, Structure and properties of ultrafine-grained materials produced by severe plastic deformation, Materials Science and Engineering A (1993), 141-148.
 R.Z. Valiev, V. I. Alexandrov, Nanostructured materials from severe plastic deformation, Nanostructured Materials, (1999) 35-40.
 J. Wongsa-Ngam, M. Kawasaki, T.G. Langdon, A comparison of microstructures and mechanical properties in a Cu–Zr alloy processed using different SPD techniques, Journal of Materials Science, (2013) 4653-4660.
 R.Z. Valiev., R.K. Islamgaliev, I.V. Alexandrov, Bulk nanostructured materials from severe plastic deformation, Progress in Materials Science, (2000) 103-189.
 A.P. Zhilyaev, G.V. Nurislamova, B.K. Kim, M.D. Baro´, J.A. Szpunar, T.G. Langdon, Experimental parameters influencing grain refinement and microstructural evolution during high-pressure torsion, Acta Materialia, (2003), 753-765.
 M. Nouri, H. Mohammadian Semnani, E. Emadoddin, Computational and experimental studies on the effect back pressure on twist extrusion process, Metals and Materials International, (2020).
 R.Z. Valiev, Developing SPD methods for processing bulk nanostructured materials with enhanced properties, Metals and Materials International, (2001), 413-420.
 A. Azushima, R. Kopp, A. Korhonen, D.Y. Yang, F. Micari, G.D. Lahoti, A.Yanagida, Severe plastic deformation (SPD) processes for metals, CIRP Annals, (2008), 716-735.
 J. Zrnik, S.V. Dobatkin, I. Mamuzić, Processing of metals by severe plastic deformation (SPD)-structure and mechanical properties respond, Journal Metalurgija, (2008), 211-216.
 R.Z. Valiev, Y. Estrin, Z. Horita, T.G. Langdon, M. J. Zechetbauer, Y.T. Zhu, Producing bulk ultrafine-grained materials by severe plastic deformation, JOM, (2006), 33-39.
 K. Edalati, M. Ashida, Z. Horita, T. Matsui, H. Kato, Wear resistance and tribological features of pure aluminum and Al–Al2O3 composites consolidated by high-pressure torsion, Wear, (2014), 83-89.
 Y. Huang, T.G. Langdon, Advances in ultrafine-grained materials, Materials Today, (2013), 85-93.
 P. Bazarnik, Y. Huang, M. Lewandowska, T.G. Langdon, Structural impact on the Hall-Petch relationship in an Al–5Mg alloy processed by high-pressure torsion, Materials Science and Engineering A, (2015), 9-15.
 S. Ghaemi Khiavi, E. Emadoddin, Microhardness distribution and finite element method analysis of Al 5452 alloy processed by unconstrained high-pressure torsion, Journal of Materials Research and Technology, (2018), 410-418.
 A. Zhilyaev, T.G. Langdon, Using high-pressure torsion for metal processing: Fundamentals and applications, Progress in Materials Science, (2008), 893–979.
 I. Balasundar, T. and Raghu, On the die design for Repetitive upsetting - extrusion (RUE) process, International Journal of Material Forming, (2011), 289-301.
 Patil, D. C., Kallannavar, V., Bhovi, P. M., Kori, S. A., and Venkateswarlu, K., Finite element analysis of ECAP, TCAP, RUE and CGP processes, IOP Conference Series: Materials Science and Engineering( 2016).
 I. Balasundar, T. Raghu, Deformation behaviour of bulk materials during repetitive upsetting-extrusion (RUE), International Journal of Material Forming, (2010), 267-278.
 I. Balasundar, T. Raghu, Strain softening in oxygen free high conductivity (OFHC) copper subjected to repetitive upsetting-extrusion (RUE) process, Materials Science and Engineering A, (2013), 114-122.
 H. Lianxi, L. Yuping, W. Erde, Y. Yang, Ultrafine grained structure and mechanical properties of a LY12 Al alloy prepared by repetitive upsetting-extrusion, Materials Science and Engineering A, (2006), 327-332.
 I. Balasundar, T. Raghu, Investigations on the extrusion defect – Axial hole or funnel, Materials & Design, (2010), 2994-3001.
 L. Zaharia, R. Comaneci, R. Chelariu, D. Luca, A new severe plastic deformation method by repetitive extrusion and upsetting, Materials Science and Engineering A, (2014), 135-142.
 I. Balasundar, T. Raghu, Severe plastic deformation (SPD) using a combination of upsetting and extrusion, International Journal of Metallurgical Engineering, (2013), 130-139.
 B. Binesh, M. Aghaie-Khafri, RUE-based semi-solid processing: Microstructure evolution and effective parameters, Materials & Design, (2016), 268-286.
 W. Gao, J. Xu, J. Teng, Z. Lu, Microstructure characteristics and mechanical properties of a 2A66 Al–Li alloy processed by continuous repetitive upsetting and extrusion, Journal of Materials Research and Technology, (2016), 2506–2515.
 G. Zhang, Z. Zhang, Y. Du, Z. Yan, X. Che, Effect of isothermal repetitive upsetting extrusion on the microstructure of Mg-12.0Gd-4.5Y-2.0Zn-0.4Zr alloy, Materials, (2018), 2092-2100.