To cite wbstats in publications use:

Jesse Piburn (2016). wbstats: Programmatic Access to the World Bank API. Oak Ridge National Laboratory. Oak Ridge, Tennessee. URL http://web.ornl.gov/sci/gist/.

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 = {2016},
    url = {http://web.ornl.gov/sci/gist/},
  }