H. K. Pathak, and Satyaj Tiwari. “Common Fixed Point and Best Simultaneous Approximations Theorems Under Releaxed Conditions”. Journal of International Academy of Physical Sciences, vol. 15, no. 5, Oct. 2011, pp. 17-22, https://www.iaps.org.in/journal/index.php/journaliaps/article/view/920.