“Preparation and Characterization of Sulfonated Polyether Ether Ketone Membranes for Fuel Cell Applications: A Comparison With Nafion® Membranes”. Journal of the Pakistan Institute of Chemical Engineers, vol. 42, no. 1, July 2014, pp. 55-62, https://www.piche.org.pk/journal/index.php/jpiche/article/view/147.