To cite package ‘europepmc’ in publications use:

  Jahn N (2023). _europepmc: R Interface to the Europe PubMed Central
  RESTful Web Service_. R package version 0.4.3, ,
  <https://github.com/ropensci/europepmc>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {europepmc: R Interface to the Europe PubMed Central RESTful Web Service},
    author = {Najko Jahn},
    year = {2023},
    note = {R package version 0.4.3, 
},
    url = {https://github.com/ropensci/europepmc},
  }