% references.bib  one placeholder entry. Replace with real sources.
@article{placeholder2026,
  author  = {Lastname, Firstname and Othername, Second},
  title   = {Placeholder Article Title},
  journal = {Journal Name},
  year    = {2026},
  volume  = {1},
  number  = {1},
  pages   = {1--10},
  doi     = {10.0000/placeholder}
}