L. Gutiérrez-Urrutia, S. Gutiérrez, and J. M. San Juan, “Influence of austenisation temperature and hold time on grain size of type 9Cr1MoVNb ferritic-martensitic steels used in supercritical boilers”, Rev. metal., vol. 37, no. 2, pp. 98–102, Apr. 2001.