International Journal of Applied Mathematics and Machine Learning[1] D. W. Cranston and D. B. West, An introduction to the discharging
method via graph coloring, Discrete Mathematics 340(4) (2017),
766-793.
DOI: https://doi.org/10.1016/j.disc.2016.11.022
[2] D. P. Sanders, On light edges and triangles in projective planar
graphs, Journal of Graph Theory 21(3) (1996), 335-342.
DOI:
https://doi.org/10.1002/(SICI)1097-0118(199603)21:3<335::AID-JGT9>3.0.
CO;2-R
[3] S. Jendrol and H.-J. Voss, Light subgraphs of graphs embedded in
the plane: A survey, Discrete Mathematics 313(4) (2013), 406-421.
DOI: https://doi.org/10.1016/j.disc.2012.11.007
