To cite cNORM in publications you can either refer to Package itself or to one or several of the primary sources:

Lenhard, A., Lenhard, W., Gary, S. (2018). Continuous Norming (cNORM). The Comprehensive R Network, Package cNORM, available: https://CRAN.R-project.org/package=cNORM

Lenhard, A., Lenhard, W., Suggate, S., & Segerer, R. (2018). A Continuous Solution to the Norming Problem. Assessment, 25(1), 112–125. https://doi.org/10.1177/1073191116656437

Lenhard, A., Lenhard, W., Gary, S. (2019). Continuous norming of psychometric tests: A simulation study of parametric and semi-parametric approaches. PLoS ONE, 14(9), e0222279. https://doi.org/10.1371/journal.pone.0222279

Lenhard, W., & Lenhard, A. (2020). Improvement of Norm Score Quality via Regression-Based Continuous Norming. Educational and Psychological Measurement, Online First, 1-33. https://doi.org/10.1177/0013164420928457

Gary, S., Lenhard, A., Lenhard, W., & Herzberg, D. S. (2023). Reducing the Bias of Norm Scores in Non-Representative Samples: Weighting as an Adjunct to Continuous Norming Methods. Assessment. https://doi.org/10.1177/10731911231153832

Gary, S., Lenhard, W., Lenhard, A. et al. A tutorial on automatic post-stratification and weighting in conventional and regression-based norming of psychometric tests. Behav Res (2023). https://doi.org/10.3758/s13428-023-02207-0

Corresponding BibTeX entries:

  @Article{,
    title = {Continuous Norming (cNORM)},
    author = {Alexandra Lenhard and Wolfgang Lenhard and Sebastian
      Gary},
    journal = {The Comprehensive R Archive Network},
    year = {2018},
    url = {https://CRAN.R-project.org/package=cNORM},
  }

  @Article{,
    title = {A continuous solution to the norming problem},
    author = {Alexandra Lenhard and Wolfgang Lenhard and Sebastian
      Suggate and Robin Segerer},
    journal = {Assessment},
    year = {2018},
    volume = {25},
    number = {1},
    pages = {112--125},
    url = {https://doi.org/10.1177/1073191116656437},
  }

  @Article{,
    title = {Continuous norming of psychometric tests: A simulation
      study of parametric and semi-parametric approaches},
    author = {Alexandra Lenhard and Wolfgang Lenhard and Sebastian
      Gary},
    journal = {PloS One},
    year = {2019},
    volume = {14},
    number = {9},
    url = {https://doi.org/10.1371/journal.pone.0222279},
  }

  @Article{,
    title = {Improvement of Norm Score Quality via Regression-Based
      Continuous Norming},
    author = {Wolfgang Lenhard and Alexandra Lenhard},
    journal = {Educational and Psychological Measurement},
    year = {2020},
    volume = {Online First},
    pages = {1-33},
    url = {https://doi.org/10.1177/0013164420928457},
  }

  @Article{,
    title = {Reducing the bias of norm scores in non-representative
      samples: Weighting as an adjunct to continuous norming methods},
    author = {Sebastian Gary and Alexandra Lenhard and Wolfgang Lenhard
      and David S. Herzberg},
    journal = {Assessment},
    year = {2023},
    volume = {Online First},
    pages = {1-33},
    url = {https://doi.org/10.1177/10731911231153832},
  }

  @Article{,
    title = {A tutorial on automatic post-stratification and weighting
      in conventional and regression-based norming of psychometric
      tests},
    author = {Sebastian Gary and Wolfgang Lenhard and Alexandra Lenhard
      and David S. Herzberg},
    journal = {Behavioral Research Methods},
    year = {2023},
    volume = {Online First},
    url = {https://doi.org/10.3758/s13428-023-02207-0},
  }