To cite package ‘free’ in publications use:

Lian Y, Yang Y, Gu Y, Fan J, Zhao Y, Platt R (2024). free: Flexible Regularized Estimating Equations. R package version 1.0.2, https://CRAN.R-project.org/package=free.

Corresponding BibTeX entry:

  @Manual{,
    title = {free: Flexible Regularized Estimating Equations},
    author = {Yi Lian and Yi Yang and Yuwen Gu and Jun Fan and Yue Zhao
      and Robert W. Platt},
    year = {2024},
    note = {R package version 1.0.2},
    url = {https://CRAN.R-project.org/package=free},
  }