3 is NP-hard

Arnaud de Mesmay, Yo'av Rieck, Eric Sedgwick, Martin Tancer. 3 is NP-hard. Journal of the ACM, 67(4), 2020. [doi]

@article{MesmayRST20,
  title = {3 is NP-hard},
  author = {Arnaud de Mesmay and Yo'av Rieck and Eric Sedgwick and Martin Tancer},
  year = {2020},
  url = {https://dl.acm.org/doi/10.1145/3396593},
  researchr = {https://researchr.org/publication/MesmayRST20},
  cites = {0},
  citedby = {0},
  journal = {Journal of the ACM},
  volume = {67},
  number = {4},
}