diff --git a/README.md b/README.md
index 8cfe281..5a9628b 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,22 @@ This module allows a user to create **2-gram** (bigram) index for faster full te
 
 pg_bigm is released under the [PostgreSQL License](https://opensource.org/licenses/postgresql), a liberal Open Source license, similar to the BSD or MIT licenses.
 
-For more information look at [the official pg_bigm web site](https://pgbigm.osdn.jp/index_en.html).
-
 ## Test Status
 [![Build Status](https://travis-ci.com/pgbigm/pg_bigm.svg?branch=master)](https://travis-ci.com/github/pgbigm/pg_bigm)
+
+## Documentation
+### English
+* [Release 1.2](https://pgbigm.github.io/pg_bigm/pg_bigm_en-1-2.html)
+* [Release 1.1](https://pgbigm.github.io/pg_bigm/pg_bigm_en-1-1.html)
+* [Release 1.0](https://pgbigm.github.io/pg_bigm/pg_bigm_en.html)
+
+### 日本語
+* [リリース1.2](https://pgbigm.github.io/pg_bigm/pg_bigm-1-2.html)
+* [リリース1.1](https://pgbigm.github.io/pg_bigm/pg_bigm-1-1.html)
+* [リリース1.0](https://pgbigm.github.io/pg_bigm/pg_bigm.html)
+
+*****
+
+Copyright (c) 2017-2023, pg_bigm Development Group
+
+Copyright (c) 2012-2016, NTT DATA Corporation
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