diff --git a/CITATION.cff b/CITATION.cff
new file mode 100644
index 0000000..a08536c
--- /dev/null
+++ b/CITATION.cff
@@ -0,0 +1,15 @@
+cff-version: 1.2.0
+message: "If you use this software, please cite it as below."
+
+title: "dems"
+abstract: "DESHIMA measurement set"
+version: 0.4.0
+date-released: 2023-07-26
+license: "MIT"
+doi: "10.5281/zenodo.8151950"
+url: "https://github.com/deshima-dev/dems"
+authors:
+  - given-names: "Akio"
+    family-names: "Taniguchi"
+    affiliation: "Nagoya University"
+    orcid: "https://orcid.org/0000-0002-9695-6183"
diff --git a/README.md b/README.md
index 2ba24a3..65737be 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,7 @@
 [![Release](https://img.shields.io/pypi/v/dems?label=Release&color=cornflowerblue&style=flat-square)](https://pypi.org/project/dems/)
 [![Python](https://img.shields.io/pypi/pyversions/dems?label=Python&color=cornflowerblue&style=flat-square)](https://pypi.org/project/dems/)
 [![Downloads](https://img.shields.io/pypi/dm/dems?label=Downloads&color=cornflowerblue&style=flat-square)](https://pepy.tech/project/dems)
+[![DOI](https://img.shields.io/badge/DOI-10.5281/zenodo.8151950-cornflowerblue?style=flat-square)](https://doi.org/10.5281/zenodo.8151950)
 [![Tests](https://img.shields.io/github/actions/workflow/status/deshima-dev/dems/tests.yaml?label=Tests&style=flat-square)](https://github.com/deshima-dev/dems/actions)
 
 DESHIMA measurement set
diff --git a/dems/__init__.py b/dems/__init__.py
index 5c5937a..c672b91 100644
--- a/dems/__init__.py
+++ b/dems/__init__.py
@@ -1,5 +1,5 @@
 __all__ = ["d1", "d2"]
-__version__ = "0.3.0"
+__version__ = "0.4.0"
 
 
 # submodules
diff --git a/dems/d2.py b/dems/d2.py
index 8cdee22..b8f808e 100644
--- a/dems/d2.py
+++ b/dems/d2.py
@@ -8,6 +8,7 @@
 
 # dependencies
 from xarray_dataclasses import AsDataArray, Attr, Coordof, Data, Dataof
+from . import __version__
 
 
 # type hints
@@ -21,7 +22,7 @@
     -5440188.022176585,
     -2475718.801708271,
 )
-DEMS_VERSION = "0.3.0"
+DEMS_VERSION = __version__
 DMERGE_VERSION = "1.0.0"
 
 
diff --git a/pyproject.toml b/pyproject.toml
index 3e8a49c..7360c68 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "dems"
-version = "0.3.0"
+version = "0.4.0"
 description = "DESHIMA measurement set"
 authors = ["Akio Taniguchi <taniguchi@a.phys.nagoya-u.ac.jp>"]
 license = "MIT"