Adjoining to (s, t)-Wythoff's game its P-positions as moves

@article{Liu2014AdjoiningT,
  title={Adjoining to (s, t)-Wythoff's game its P-positions as moves},
  author={Wen An Liu and Xiao Zhao},
  journal={Discrete Applied Mathematics},
  year={2014},
  volume={179},
  pages={28-43}
}