Reverse mathematics and Isbell's zig-zag theorem

Takashi Sato. Reverse mathematics and Isbell's zig-zag theorem. Math. Log. Q., 60(4-5):348-353, 2014. [doi]

@article{Sato14a,
  title = {Reverse mathematics and Isbell's zig-zag theorem},
  author = {Takashi Sato},
  year = {2014},
  doi = {10.1002/malq.201300071},
  url = {http://dx.doi.org/10.1002/malq.201300071},
  researchr = {https://researchr.org/publication/Sato14a},
  cites = {0},
  citedby = {0},
  journal = {Math. Log. Q.},
  volume = {60},
  number = {4-5},
  pages = {348-353},
}