M. RAMZAN, H. M. YOUNUS, S. KHAN, and M. RAFIQ. “A Note on Proper Homothetic Vector Fields of Reboucus Space-Time by Using Lorentzian Manifolds”. Sindh University Research Journal - SURJ (Science Series), vol. 48, no. 1, Mar. 2016, https://sujo.usindh.edu.pk/index.php/SURJ/article/view/4964.