To cite wbstats in publications use:

Piburn J (2020). wbstats: Programmatic Access to the World Bank API. Oak Ridge National Laboratory, Oak Ridge, Tennessee. https://doi.org/10.11578/dc.20171025.1827.

Corresponding BibTeX entry:

  @Manual{,
    title = {wbstats: Programmatic Access to the World Bank API},
    author = {Jesse Piburn},
    organization = {Oak Ridge National Laboratory},
    address = {Oak Ridge, Tennessee},
    year = {2020},
    url = {https://doi.org/10.11578/dc.20171025.1827},
  }