To cite package ‘NPCDTools’ in publications use:

  Chiu C, Xiao W, Wen X, Wang Y (2024). _NPCDTools: The Nonparametric
  Classification Methods for Cognitive Diagnosis_. R package version
  1.0, <https://CRAN.R-project.org/package=NPCDTools>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {NPCDTools: The Nonparametric Classification Methods for Cognitive Diagnosis},
    author = {Chia-Yi Chiu and Weixuan Xiao and Xiran Wen and Yu Wang},
    year = {2024},
    note = {R package version 1.0},
    url = {https://CRAN.R-project.org/package=NPCDTools},
  }