@Misc{ 
  HanYin25,
  author = { Han, Bangxian and Yin, Liming },
  title = { On the Structure of Busemann Spaces with Non-Negative Curvature },
  journal = {  },
  year = { 2025 },
  pages = { 46 },
  URL = { http://cvgmt.sns.it/paper/7257/ },
  note = { cvgmt preprint}
}