Please cite both the liureg related paper and the liureg package: To cite liureg article in publications use:

Imdad MU, Aslam M (2018). liureg: Liu Regression with Liu Biasing Parameters and Statistics. R package version 1.1.2, https://CRAN.R-project.org/package=liureg.

Imdadullah M, Aslam M (2017). “liureg: A Comprehensive R Package for the Liu Estimation of Linear Regression Model with Collinear Regressors.” The R Journal, 9(2), 232-247. https://journal.r-project.org/archive/2017/RJ-2017-048/index.html.

Corresponding BibTeX entries:

  @Manual{,
    title = {{liureg}: Liu Regression with Liu Biasing Parameters and
      Statistics},
    author = {M. U. Imdad and M. Aslam},
    year = {2018},
    note = {R package version 1.1.2},
    url = {https://CRAN.R-project.org/package=liureg},
  }

  @Article{,
    title = {liureg: A Comprehensive R Package for the Liu Estimation
      of Linear Regression Model with Collinear Regressors},
    author = {M. Imdadullah and M. Aslam},
    journal = {The R Journal},
    year = {2017},
    volume = {9(2)},
    pages = {232-247},
    url =
      {https://journal.r-project.org/archive/2017/RJ-2017-048/index.html},
  }