diff --git a/DESCRIPTION b/DESCRIPTION
index 1208563..7fa9b31 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: secretbase
 Type: Package
 Title: Cryptographic Hash and Extendable-Output Functions
-Version: 0.1.0
+Version: 0.1.0.9000
 Description: SHA-3 cryptographic hash and SHAKE256 extendable-output functions
     (XOF). The SHA-3 Secure Hash Standard was published by the National
     Institute of Standards and Technology (NIST) in 2015 at
diff --git a/NEWS.md b/NEWS.md
index 3c7906d..ab52718 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,3 +1,5 @@
+# secretbase 0.1.0.9000 (development)
+
 # secretbase 0.1.0
 
 * Initial CRAN release.
diff --git a/R/base.R b/R/base.R
index 54969df..57792f0 100644
--- a/R/base.R
+++ b/R/base.R
@@ -44,8 +44,7 @@
 
 #' Cryptographic Hashing Using the SHA-3 Algorithm
 #'
-#' Returns a SHA-3 hash of the supplied R object. Implementated from code used
-#'     by the the 'Mbed TLS' library under the Trusted Firmware Project.
+#' Returns a SHA-3 hash of the supplied R object.
 #'
 #' @param x an object.
 #' @param bits [default 256L] output size of the returned hash - uses the
@@ -59,8 +58,8 @@
 #'
 #' @return A character string, raw or integer vector depending on 'convert'.
 #'
-#' @details For argument 'x', a character string or raw vector (with no
-#'     attributes) is hashed 'as is'.
+#' @details A character string or raw vector (with no attributes) is hashed 'as
+#'     is'.
 #'     
 #'     All other objects are hashed in-place, in a 'streaming' fashion, by R
 #'     serialization but without allocation of the serialized object. To ensure
diff --git a/README.Rmd b/README.Rmd
index 5709b7e..4976543 100644
--- a/README.Rmd
+++ b/README.Rmd
@@ -20,6 +20,7 @@ knitr::opts_chunk$set(
 [![secretbase status badge](https://shikokuchuo.r-universe.dev/badges/secretbase?color=e4723a)](https://shikokuchuo.r-universe.dev/secretbase)
 [![R-CMD-check](https://github.com/shikokuchuo/secretbase/workflows/R-CMD-check/badge.svg)](https://github.com/shikokuchuo/secretbase/actions)
 [![codecov](https://codecov.io/gh/shikokuchuo/secretbase/graph/badge.svg)](https://app.codecov.io/gh/shikokuchuo/secretbase)
+[![DOI](https://zenodo.org/badge/745691432.svg)](https://zenodo.org/doi/10.5281/zenodo.10553139)
 <!-- badges: end -->
 
 SHA-3 cryptographic hash and SHAKE256 extendable-output functions (XOF).
diff --git a/README.md b/README.md
index e3fbf34..4e2b32b 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ status](https://www.r-pkg.org/badges/version/secretbase?color=42147b)](https://C
 badge](https://shikokuchuo.r-universe.dev/badges/secretbase?color=e4723a)](https://shikokuchuo.r-universe.dev/secretbase)
 [![R-CMD-check](https://github.com/shikokuchuo/secretbase/workflows/R-CMD-check/badge.svg)](https://github.com/shikokuchuo/secretbase/actions)
 [![codecov](https://codecov.io/gh/shikokuchuo/secretbase/graph/badge.svg)](https://app.codecov.io/gh/shikokuchuo/secretbase)
+[![DOI](https://zenodo.org/badge/745691432.svg)](https://zenodo.org/doi/10.5281/zenodo.10553139)
 <!-- badges: end -->
 
 SHA-3 cryptographic hash and SHAKE256 extendable-output functions (XOF).
diff --git a/inst/CITATION b/inst/CITATION
index f47969a..42a51fd 100644
--- a/inst/CITATION
+++ b/inst/CITATION
@@ -3,4 +3,4 @@ bibentry(bibtype = "Manual",
          author = person("Charlie", "Gao"),
          year = 2024,
          note = sprintf("R package version %s", meta$Version),
-         url = "https://shikokuchuo.net/secretbase/")
+         url = "https://doi.org/10.5281/zenodo.10553139")
diff --git a/man/sha3.Rd b/man/sha3.Rd
index 6f5fa01..5bcd1f2 100644
--- a/man/sha3.Rd
+++ b/man/sha3.Rd
@@ -23,12 +23,11 @@ vector, or if NA, a vector of (32-bit) integer values.}
 A character string, raw or integer vector depending on 'convert'.
 }
 \description{
-Returns a SHA-3 hash of the supplied R object. Implementated from code used
-    by the the 'Mbed TLS' library under the Trusted Firmware Project.
+Returns a SHA-3 hash of the supplied R object.
 }
 \details{
-For argument 'x', a character string or raw vector (with no
-    attributes) is hashed 'as is'.
+A character string or raw vector (with no attributes) is hashed 'as
+    is'.
     
     All other objects are hashed in-place, in a 'streaming' fashion, by R
     serialization but without allocation of the serialized object. To ensure