To cite the loo R package:

  Vehtari A, Gabry J, Magnusson M, Yao Y, Bürkner P, Paananen T, Gelman
  A (2024). “loo: Efficient leave-one-out cross-validation and WAIC for
  Bayesian models.” R package version 2.8.0.9000,
  <https://mc-stan.org/loo/>.

A BibTeX entry for LaTeX users is

  @Misc{,
    title = {loo: Efficient leave-one-out cross-validation and WAIC for Bayesian models},
    author = {Aki Vehtari and Jonah Gabry and Måns Magnusson and Yuling Yao and Paul-Christian Bürkner and Topi Paananen and Andrew Gelman},
    year = {2024},
    note = {R package version 2.8.0.9000},
    url = {https://mc-stan.org/loo/},
  }

To cite the loo paper:

  Vehtari A, Gelman A, Gabry J (2017). “Practical Bayesian model
  evaluation using leave-one-out cross-validation and WAIC.”
  _Statistics and Computing_, *27*, 1413-1432.
  doi:10.1007/s11222-016-9696-4
  <https://doi.org/10.1007/s11222-016-9696-4>.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Practical Bayesian model evaluation using leave-one-out cross-validation and WAIC},
    author = {Aki Vehtari and Andrew Gelman and Jonah Gabry},
    year = {2017},
    journal = {Statistics and Computing},
    volume = {27},
    issue = {5},
    pages = {1413--1432},
    doi = {10.1007/s11222-016-9696-4},
  }

To cite the stacking paper:

  Yao Y, Vehtari A, Simpson D, Gelman A (2017). “Using stacking to
  average Bayesian predictive distributions.” _Bayesian Analysis_.
  doi:10.1214/17-BA1091 <https://doi.org/10.1214/17-BA1091>.

A BibTeX entry for LaTeX users is

  @Article{,
    title = {Using stacking to average Bayesian predictive distributions},
    author = {Yuling Yao and Aki Vehtari and Daniel Simpson and Andrew Gelman},
    year = {2017},
    journal = {Bayesian Analysis},
    doi = {10.1214/17-BA1091},
  }