@article{FujiiKimKojimaetal.2024,
  author    = {Koichi Fujii and Sunyoung Kim and Masakazu Kojima and Hans D. Mittelmann and Yuji Shinano},
  title     = {An exceptionally difficult binary quadratic optimization problem with symmetry: a challenge for the largest unsolved QAP instance Tai256c},
  journal   = {Optimization Letters},
  doi       = {10.1007/s11590-024-02157-2},
  year        = {2024},
  note        = {epub ahead of print}
}