citHeader("To cite the 'PP' package in publications use:")

year <- sub(".*(2[[:digit:]]{3})-.*", "\\1", meta$Date, perl = TRUE)
vers <- paste("R package version", meta$Version)

citEntry(entry="Manual",
         title = "PP: Estimation of person parameters for the 1,2,3,4-PL model and the GPCM.",
         author = personList(as.person("Manuel Reif and Jan Steinfeld")),
         year = year,
         note = vers,
    url  = "https://github.com/jansteinfeld/PP",        
         textVersion =
         paste0("Reif, M. and Steinfeld, J. (",
               year,
               "). PP: Estimation of person parameters for the 1,2,3,4-PL model and the GPCM. ",
               vers, "."," https://github.com/jansteinfeld/PP"))