To cite package ‘lettervalue’ in publications use:

Sassi G (2023). lettervalue: Computing Letter Values. R package version 0.2.1, https://github.com/gilberto-sassi/lettervalue.

Corresponding BibTeX entry:

  @Manual{,
    title = {lettervalue: Computing Letter Values},
    author = {Gilberto Sassi},
    year = {2023},
    note = {R package version 0.2.1},
    url = {https://github.com/gilberto-sassi/lettervalue},
  }