Team, S. “A Common Fixed Point Theorem for a Pair of Nonself Multi-Valued Mappings: M. Imdad, Ladlay Khan”. Thai Journal of Mathematics, vol. 3, no. 2, Dec. 2005, pp. 193-9, https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/24.