Bondar, Kiramkumar Laxmanrao, et al. “COUPLED COINSIDENCE POINT THEOREM FOR NONLINEAR CONTRACTION IN PARTIALLY ORDERED METRIC SPACES”. Journal of Global Research in Mathematical Archives(JGRMA), vol. 1, no. 2, Mar. 2013, pp. 23-32, https://jgrma.com/index.php/jgrma/article/view/10.