Team, S. “Convergence Theorems for Finite Family of Multivalued K-Strictly Pseudononspreading Mappings in R-Trees: Khanitin Samanmit”. Thai Journal of Mathematics, vol. 13, no. 3, Dec. 2015, pp. 581-9, https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/534.