To cite the 'STARTS' package in publications use:

Robitzsch A, Luedtke O (2019). STARTS: Functions for the STARTS Model. R package version 1.2-35, https://CRAN.R-project.org/package=STARTS.

Corresponding BibTeX entry:

  @Manual{starts_R package version 1.2-35,
    title = {STARTS: Functions for the STARTS Model},
    author = {Alexander Robitzsch and Oliver Luedtke},
    year = {2019},
    note = {R package version 1.2-35},
    url = {https://CRAN.R-project.org/package=STARTS},
  }