Argyros, Ioannis K., and Saïd Hilout. “On the Convergence of Steffensen-Type Methods Using Recurrent Functions Nonexpansive Mappings”. Rev. Anal. Numér. Théor. Approx., vol. 38, no. 2, Aug. 2009, pp. 130-43, https://doi.org/10.33993/jnaat382-908.