Hanano Puzzle is NP-hard

Ziwen Liu, Chao Yang 0003. Hanano Puzzle is NP-hard. Inf. Process. Lett., 145:6-10, 2019. [doi]

@article{LiuY19-3,
  title = {Hanano Puzzle is NP-hard},
  author = {Ziwen Liu and Chao Yang 0003},
  year = {2019},
  doi = {10.1016/j.ipl.2019.01.003},
  url = {https://doi.org/10.1016/j.ipl.2019.01.003},
  researchr = {https://researchr.org/publication/LiuY19-3},
  cites = {0},
  citedby = {0},
  journal = {Inf. Process. Lett.},
  volume = {145},
  pages = {6-10},
}