diff --git a/R/families.R b/R/families.R
index 82658a4b4..8bbf58e09 100644
--- a/R/families.R
+++ b/R/families.R
@@ -70,6 +70,23 @@ lognormal <- function(link = "log") {
 #' @rdname families
 #' @examples
 #' gengamma(link = "log")
+#' @details
+#' The `gengamma()` family was implemented by J.T. Thorson and uses the Prentice
+#' (1974) parameterization such that the lognormal occurs as the internal
+#' parameter `gengamma_Q` (reported in `print()` as "Generalized gamma lambda")
+#' approaches 0.
+#'
+#' @references
+#'
+#' *Generalized gamma family*:
+#'
+#' Prentice, R.L. 1974. A log gamma model and its maximum likelihood estimation.
+#' Biometrika 61(3): 539–544. \doi{10.1093/biomet/61.3.539}
+#'
+#' Stacy, E.W. 1962. A Generalization of the Gamma Distribution. The Annals of
+#' Mathematical Statistics 33(3): 1187–1192. Institute of Mathematical
+#' Statistics.
+
 gengamma <- function(link = "log") {
   linktemp <- substitute(link)
   if (!is.character(linktemp))
diff --git a/man/families.Rd b/man/families.Rd
index a59801eb8..bcff89705 100644
--- a/man/families.Rd
+++ b/man/families.Rd
@@ -87,6 +87,11 @@ A list with elements common to standard R family objects including \code{family}
 Additional families compatible with \code{\link[=sdmTMB]{sdmTMB()}}.
 }
 \details{
+The \code{gengamma()} family was implemented by J.T. Thorson and uses the Prentice
+(1974) parameterization such that the lognormal occurs as the internal
+parameter \code{gengamma_Q} (reported in \code{print()} as "Generalized gamma lambda")
+approaches 0.
+
 The families ending in \verb{_mix()} are 2-component mixtures where each
 distribution has its own mean but a shared scale parameter.
 (Thorson et al. 2011). See the model-description vignette for details.
@@ -134,6 +139,15 @@ delta_poisson_link_lognormal()
 delta_beta()
 }
 \references{
+\emph{Generalized gamma family}:
+
+Prentice, R.L. 1974. A log gamma model and its maximum likelihood estimation.
+Biometrika 61(3): 539–544. \doi{10.1093/biomet/61.3.539}
+
+Stacy, E.W. 1962. A Generalization of the Gamma Distribution. The Annals of
+Mathematical Statistics 33(3): 1187–1192. Institute of Mathematical
+Statistics.
+
 \emph{Families ending in \verb{_mix()}}:
 
 Thorson, J.T., Stewart, I.J., and Punt, A.E. 2011. Accounting for fish shoals