Aurangzaib, M., S. M. Murshid, and S. A. Urooj. “Heat and Mass Transfer Over an Unsteady Stretching Permeable Surface With Non-Uniform Heat Source/Sink and Thermal Radiation”. The Nucleus, vol. 51, no. 4, Oct. 2014, pp. 411-7, http://thenucleuspak.org.pk/index.php/Nucleus/article/view/668.