To cite package ‘alfred’ in publications use:

Kleen O (2023). alfred: Downloading Time Series from ALFRED Database for Various Vintages. R package version 0.2.1, https://github.com/onnokleen/alfred.

Corresponding BibTeX entry:

  @Manual{,
    title = {alfred: Downloading Time Series from ALFRED Database for
      Various Vintages},
    author = {Onno Kleen},
    year = {2023},
    note = {R package version 0.2.1},
    url = {https://github.com/onnokleen/alfred},
  }