@misc{Yang2026Lee2ProofNote,
  author = {Yang, Shifu},
  title = {{Nonexistence of Perfect Two-Error-Correcting Lee Codes}},
  howpublished = {Mathematical proof note, version 1.0},
  year = {2026},
  month = oct,
  note = {Dated October 16, 2026},
  url = {https://github.com/stalin1943/Coding-Theory-Proof-Notes/blob/main/perfect-radius-two-lee-codes/proof.pdf}
}