To cite the lmom package use:

J. R. M. Hosking (2019). L-Moments. R package, version 2.8. URL: https://CRAN.R-project.org/package=lmom.

Corresponding BibTeX entry:

  @Manual{,
    title = {L-Moments},
    author = {J. R. M. Hosking},
    year = {2019},
    note = {R package, version 2.8},
    url = {https://CRAN.R-project.org/package=lmom},
  }