Choudhary, R. K., V. Kain, and R. Hubli. “Formation of Alumina-Aluminide Coatings on Ferritic-Martensitic T91 Steel”. Journal of Mining and Metallurgy, Section B: Metallurgy, Vol. 50, no. 2, Oct. 2014, p. 165, https://aseestant.ceon.rs/index.php/jmm/article/view/6497.