1. Akram, M.: Bipolar fuzzy graphs. J. Inf. Sci. 181(24), 5548–5564 (2011)
2. Akram, M.: Bipolar fuzzy graphs with applications. Knowl. Based Syst. 39, 1–8 (2013)
3. Akram, M., Dudek, W.A.: Regular bipolar fuzzy graphs. Neural Comput. Appl. 21(1), 197–205 (2012)
4. Akram, M., Li, S.-G., Shum, K.: Antipodal bipolar fuzzy graphs. Ital. J. Pure Appl. Math. 31(56), 425–438 (2013)
5. Akram, M., Alshehri, N., Davvaz, B., Ashraf, A.: Bipolar fuzzy digraphs in decision support systems. J. Mult. Valued Logic Syst. 27, 531–551 (2016)