# year
i <- regexpr("(?<=\\s{1})\\d{4}(?=-{1})", meta$Built, perl = TRUE)
year <- substring(meta$Built, i, i + 3)

# version
vers <- meta$Version
if(is.null(vers))
  vers <- packageVersion("eulerr")
note <- paste("R package version", vers)

citHeader("To cite eulerr in publications, please use:")

bibentry(
  bibtype      = "Manual",
  title        = "{eulerr}: Area-Proportional {Euler} and {Venn} Diagrams with Ellipses",
  author       = personList(as.person("Johan Larsson")),
  year         = year,
  note         = note,
  url          = "https://cran.r-project.org/package=eulerr"
)
