Al-bar, J. A., Al-kenani, A. N., Muthana, N. M., Praeger, C. E., & Spiga, P. (2016). Finite Edge-Transitive Oriented Graphs of Valency Four: a Global Approach. The Electronic Journal of Combinatorics, 23(1), P1.10. https://doi.org/10.37236/4779