To cite qualR in publications use:

Gavidia-Calderón, M., Schuch, D., Andrade, Maria de Fatima (2022). qualR: An R package to download Sao Paulo and Rio de Janeiro air pollution data. URL: https://docs.ropensci.org/qualR/

Corresponding BibTeX entry:

  @Manual{,
    title = {qualR: An R package to download São Paulo and Rio de
      Janeiro air pollution data},
    doi = {10.5281/zenodo.5904262},
    author = {Mario Gavidia-Calderón and Daniel Schuch and Maria de
      Fatima Andrade},
    year = {2022},
    url = {https://docs.ropensci.org/qualR/},
  }