#'
#' @return An estimate of the basic reproduction number (R0).
#'
-#' @references
-#' [Fisman et al. (PloS One, 2013)](
+#' @references [Fisman et al. (PloS One, 2013)](
#' https://doi.org/10.1371/journal.pone.0083622)
#'
#' @seealso [idea()] for a similar method.