To cite spiro in publications use:

Nolte S (2023). “spiro: An R package for analyzing data from cardiopulmonary exercise testing.” Journal of Open Source Software, 8(81), 5089. doi:10.21105/joss.05089, https://joss.theoj.org/papers/10.21105/joss.05089.

Corresponding BibTeX entry:

  @Article{,
    title = {spiro: An R package for analyzing data from
      cardiopulmonary exercise testing},
    author = {Simon Nolte},
    year = {2023},
    volume = {8},
    number = {81},
    pages = {5089},
    journal = {Journal of Open Source Software},
    url = {https://joss.theoj.org/papers/10.21105/joss.05089},
    doi = {10.21105/joss.05089},
  }