To cite echor in publications use:

  Schramm, Michael (2023).  echor: Access EPA 'ECHO' Data.
  doi:10.5281/zenodo.3635017

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {{echor}: Access EPA 'ECHO' Data},
    author = {Michael Schramm},
    year = {2022},
    url = {https://CRAN.R-project.org/package=echor},
    do1 = {10.5281/zenodo.3635017},
    note = {R package version 0.1.7},
  }