To cite package greekLetters in publications use:

Kévin Allan Sales Rodrigues (2020).

greekLetters: routines for writing Greek letters and mathematical symbols on the RStudio and RGui. R package version 0.0.7.

Corresponding BibTeX entry:

@Manual{, title = {greekLetters: routines for writing Greek letters and mathematical symbols on the RStudio and RGui}, author = {{Kévin Allan Sales Rodrigues}}, year = {2020}, note = {R package version 0.0.7}, }