To cite spc4sts in publications use:

Bui AT, Apley DW (2021). “spc4sts: Statistical Process Control for Stochastic Textured Surfaces in R.” Journal of Quality Technology, 53, 219–242. doi:10.1080/00224065.2019.1707730.

Corresponding BibTeX entry:

  @Article{,
    title = {{spc4sts}: Statistical Process Control for Stochastic
      Textured Surfaces in R},
    author = {Anh Tuan Bui and Daniel W. Apley},
    journal = {Journal of Quality Technology},
    year = {2021},
    volume = {53},
    issue = {3},
    pages = {219--242},
    doi = {10.1080/00224065.2019.1707730},
  }