Păvăloiu, Ion. “Aitken-Steffensen Type Methods for Nondifferentiable Functions (I)”. Rev. Anal. Numér. Théor. Approx. 31, no. 1 (February 1, 2002): 109–114. Accessed August 12, 2022. https://ictp.acad.ro/jnaat/journal/article/view/2002-vol31-no1-art12.