To cite package ‘OnlineSurr’ in publications use:

  Santos Jr. SV, Parast L (2026). "A Causal Framework for Evaluating
  Jointly Longitudinal Outcomes and Surrogate Markers: A State-Space
  Approach." 2604.12882.

A BibTeX entry for LaTeX users is

  @Misc{,
    title = {A Causal Framework for Evaluating Jointly Longitudinal Outcomes and Surrogate Markers: A State-Space Approach},
    author = {Silvaneo V. dos {Santos Jr.} and Layla Parast},
    eprint = {2604.12882},
    archiveprefix = {arXiv},
    primaryclass = {stat.ME},
    rl = {https://arxiv.org/abs/2604.12882},
    year = {2026},
  }