Balázs, M., and G. Goldner. “On Approximate Solving by Sequences the Equations in Banach Spaces”.
Anal. Numér. Théor. Approx. 8, no. 1 (February 1, 1979): 27–31. Accessed April 15, 2025.
https://ictp.acad.ro/jnaat/journal/article/view/1979-vol8-no1-art2.