Bhowmik, B., and S. Nag Chowdhury. “Prograph Based Analysis of Single Source Shortest Path Problem With Few Distinct Positive Lengths”. Engineering, Technology & Applied Science Research 1, no. 4 (August 16, 2011): 90–97. Accessed July 18, 2024. https://etasr.com/index.php/ETASR/article/view/41.