Ringel's Graph Conjecture Proved After 60 Years (2020)(quantamagazine.org)
quantamagazine.org
Ringel's Graph Conjecture Proved After 60 Years (2020)
https://www.quantamagazine.org/mathematicians-prove-ringels-graph-theory-conjecture-20200219/
1 comments
And arxiv paper, which has a surprisingly readable Introduction section: https://arxiv.org/abs/2001.02665