To cite the current, hierarchical ctsem use:

  Driver CC, Voelkle MC (2018). “Hierarchical Bayesian continuous time
  dynamic modeling.” _Psychological Methods_, *23*(4), 774-799.
  doi:10.1037/met0000168 <https://doi.org/10.1037/met0000168>.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Hierarchical {{Bayesian}} continuous time dynamic modeling.},
    author = {Charles C. Driver and Manuel C. Voelkle},
    journal = {Psychological Methods},
    year = {2018},
    volume = {23},
    number = {4},
    pages = {774-799},
    doi = {10.1037/met0000168},
  }

To cite the original ctsem use:

  Driver CC, Oud JHL, Voelkle MC (2017). “Continuous Time Structural
  Equation Modeling with R package ctsem.” _Journal of Statistical
  Software_, *77*(5), 1-35. doi:10.18637/jss.v077.i05
  <https://doi.org/10.18637/jss.v077.i05>.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Continuous Time Structural Equation Modeling with {R} package {ctsem}},
    author = {Charles C. Driver and Johan H. L. Oud and Manuel C. Voelkle},
    journal = {Journal of Statistical Software},
    year = {2017},
    volume = {77},
    number = {5},
    pages = {1--35},
    doi = {10.18637/jss.v077.i05},
  }

To cite the current manual use:

  Driver CC, Voelkle MC (2021). “Hierarchical continuous time
  modeling.” In Rauthmann JF (ed.), _The Handbook of Personality
  Dynamics and Processes_, 887-908. Academic Press. ISBN
  978-0-12-813995-0. doi:10.1016/B978-0-12-813995-0.00034-0
  <https://doi.org/10.1016/B978-0-12-813995-0.00034-0>.

A BibTeX entry for LaTeX users is

  @InCollection{,
    title = {Hierarchical continuous time modeling},
    editor = {John F. Rauthmann},
    booktitle = {The Handbook of Personality Dynamics and Processes},
    publisher = {Academic Press},
    pages = {887-908},
    year = {2021},
    isbn = {978-0-12-813995-0},
    doi = {10.1016/B978-0-12-813995-0.00034-0},
    author = {Charles C. Driver and Manuel C. Voelkle},
  }