Chidume, C.E., and M.E. Okpala. “ON A GENERAL CLASS OF MULTI-VALUED STRICTLY PSEUDOCONTRACTIVE MAPPINGS”. Journal of Nonlinear Analysis and Optimization: Theory & Applications (JNAO) 5, no. 2 (September 30, 2014): 7–20. accessed September 2, 2026. https://ph03.tci-thaijo.org/index.php/jnao/article/view/2746.