1. J.H. Andrew, J. Iron Steel Inst. 86(II), 210 (1912)
2. F. Adcock, J. Iron Steel Inst. 114, 119–126 (1926)
3. J. Fresher, Ch., Kubisch, Berg und Hüttenmänn. M. H. 108, 361–380 (1963)
4. H.H. Uhlig, R.A. White, TASM 52, 830 (1960)
5. T. Rashev, High nitrogen steels (Metallurgy under Pressure, Publishing House of Bulgarian Academy of Sciences, Sofia, 1995)