Prema, A., and M. V. Ramana Murthy. “Implementing Mathematical Morphology Techniques to Detect Cracks in Underground Pipeline Images Automatically”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 13, no. 1, Mar. 2014, pp. 351-6, https://www.gssrr.org/JournalOfBasicAndApplied/article/view/1966.