diff --git a/www/reference/openjij/index.html b/www/reference/openjij/index.html
index a18f8da..4e38bdb 100644
--- a/www/reference/openjij/index.html
+++ b/www/reference/openjij/index.html
@@ -2376,7 +2376,7 @@ <h3>Attributes<a class="headerlink" href="#attributes" title="Permalink to this
 represented as a column of type dict.</p>
 </dd>
 <dt class="field-even">Returns</dt>
-<dd class="field-even"><p><code class="xref py py-obj docutils literal notranslate"><span class="pre">pandas.DataFrame</span></code>.</p>
+<dd class="field-even"><p><a class="reference external" href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.html#pandas.DataFrame" title="(in pandas v1.4.4)"><code class="xref py py-obj docutils literal notranslate"><span class="pre">pandas.DataFrame</span></code></a>.</p>
 </dd>
 </dl>
 <p class="rubric">Examples</p>
diff --git a/www/reference/openjij/sampler/index.html b/www/reference/openjij/sampler/index.html
index b5d2f2b..fda0920 100644
--- a/www/reference/openjij/sampler/index.html
+++ b/www/reference/openjij/sampler/index.html
@@ -2167,7 +2167,7 @@ <h3>Functions<a class="headerlink" href="#functions" title="Permalink to this he
 represented as a column of type dict.</p>
 </dd>
 <dt class="field-even">Returns</dt>
-<dd class="field-even"><p><code class="xref py py-obj docutils literal notranslate"><span class="pre">pandas.DataFrame</span></code>.</p>
+<dd class="field-even"><p><a class="reference external" href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.html#pandas.DataFrame" title="(in pandas v1.4.4)"><code class="xref py py-obj docutils literal notranslate"><span class="pre">pandas.DataFrame</span></code></a>.</p>
 </dd>
 </dl>
 <p class="rubric">Examples</p>
diff --git a/www/reference/openjij/sampler/response/index.html b/www/reference/openjij/sampler/response/index.html
index f3bf330..5da17e6 100644
--- a/www/reference/openjij/sampler/response/index.html
+++ b/www/reference/openjij/sampler/response/index.html
@@ -1676,7 +1676,7 @@ <h3>Classes<a class="headerlink" href="#classes" title="Permalink to this headli
 represented as a column of type dict.</p>
 </dd>
 <dt class="field-even">Returns</dt>
-<dd class="field-even"><p><code class="xref py py-obj docutils literal notranslate"><span class="pre">pandas.DataFrame</span></code>.</p>
+<dd class="field-even"><p><a class="reference external" href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.html#pandas.DataFrame" title="(in pandas v1.4.4)"><code class="xref py py-obj docutils literal notranslate"><span class="pre">pandas.DataFrame</span></code></a>.</p>
 </dd>
 </dl>
 <p class="rubric">Examples</p>