To cite package ‘APML0’ in publications use:

  Li X, Xie S, Zeng D, Wang Y (2018). “Efficient l0-norm feature
  selection based on augmented and penalized minimization.” _Statistics
  in Medicine_, *37*(3), 473-486. doi:10.1002/sim.7526
  <https://doi.org/10.1002/sim.7526>.
  <https://onlinelibrary.wiley.com/doi/abs/10.1002/sim.7526>.

A BibTeX entry for LaTeX users is

  @Article{,
    author = {Xiang Li and Shanghong Xie and Donglin Zeng and Yuanjia Wang},
    title = {Efficient l0-norm feature selection based on augmented and penalized minimization},
    journal = {Statistics in Medicine},
    volume = {37},
    number = {3},
    pages = {473--486},
    year = {2018},
    doi = {10.1002/sim.7526},
    url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/sim.7526},
  }