Bellas, L., G. Castro, L. Mera, J. L. Mier, A. García, and A. Varela. “Comparative Study of AISI 4340 and AISI 347 Nitrocarburizing by Tenifer-QPQ® Process”. Revista De Metalurgia, vol. 55, no. 1, Mar. 2019, p. e136, doi:10.3989/revmetalm.136.