To cite the 'cIRT' R package and methodology in publications use:

Culpepper SA, Balamuta J (2015). cIRT: Choice Item Response Theory.

Culpepper S, Balamuta J (2015). “A Hierarchical Model for Accuracy and Choice on Standardized Tests.” Psychometrika, 1–26. ISSN 0033-3123, doi:10.1007/s11336-015-9484-7, http://dx.doi.org/10.1007/s11336-015-9484-7.

Corresponding BibTeX entries:

  @Manual{,
    title = {{cIRT: Choice Item Response Theory}},
    author = {Steven Andrew Culpepper and James Balamuta},
    year = {2015},
  }

  @Article{2015culpepper,
    title = {A Hierarchical Model for Accuracy and Choice on
      Standardized Tests},
    author = {Steven Andrew Culpepper and James Joseph Balamuta},
    issn = {0033-3123},
    journal = {Psychometrika},
    year = {2015},
    pages = {1--26},
    doi = {10.1007/s11336-015-9484-7},
    url = {http://dx.doi.org/10.1007/s11336-015-9484-7},
    keywords = {high-stakes testing; item response theory; Thurstonian
      models; Bayesian statistics; choice},
    language = {English},
    publisher = {Springer US},
  }