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