To cite ppsynth in publications use:

  Grier, K. B. (2026). Correlated Weights: Partial Pooling for
  Synthetic Control with Multiple Outcomes. Working paper, Texas Tech
  University.
  https://papers.ssrn.com/sol3/papers.cfm?abstract_id=7149398

A BibTeX entry for LaTeX users is

  @Unpublished{,
    title = {Correlated Weights: Partial Pooling for Synthetic Control with Multiple Outcomes},
    author = {Kevin B. Grier},
    year = {2026},
    note = {Working paper, Texas Tech University},
    url = {https://papers.ssrn.com/sol3/papers.cfm?abstract_id=7149398},
  }