Ali, Amjad, and Atta ur Rehman. 2016. “Classification of Cylindrically Symmetric Marder Type Spacetimes According to Their Proper Homothetic Vector Fields”. International Journal of Sciences: Basic and Applied Research (IJSBAR) 25 (3):13-19. https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/5247.