To cite the package 'fourPNO' in publications use:

Culpepper SA (2019). fourPNO: Bayesian 4 Parameter Item Response Model.

Culpepper SA (2016). “Revisiting the 4-Parameter Item Response Model: Bayesian Estimation and Application.” Psychometrika, 81(4), 1142–1163. ISSN 1860-0980, doi: 10.1007/s11336-015-9477-6, http://dx.doi.org/10.1007/s11336-015-9477-6.

Corresponding BibTeX entries:

  @Manual{,
    title = {{fourPNO: Bayesian 4 Parameter Item Response Model}},
    author = {Steven Andrew Culpepper},
    year = {2019},
  }
  @Article{,
    title = {Revisiting the 4-Parameter Item Response Model: Bayesian
      Estimation and Application},
    author = {Steven Andrew Culpepper},
    journal = {Psychometrika},
    year = {2016},
    volume = {81},
    number = {4},
    pages = {1142--1163},
    issn = {1860-0980},
    doi = {10.1007/s11336-015-9477-6},
    url = {http://dx.doi.org/10.1007/s11336-015-9477-6},
  }