diff --git a/content/labs/visualization/2020-06-13-different-types-of-graphs.md b/content/labs/visualization/2020-06-13-different-types-of-graphs.md
index e1caf54..d6542cf 100644
--- a/content/labs/visualization/2020-06-13-different-types-of-graphs.md
+++ b/content/labs/visualization/2020-06-13-different-types-of-graphs.md
@@ -485,8 +485,11 @@ chart=true
 
 
 ## 参考
+
+### 参考リンク
 - [Chart.jsでグラフを描画してみた - Qiita](https://qiita.com/Haruka-Ogawa/items/59facd24f2a8bdb6d369#3-2-%E6%A3%92%E3%82%B0%E3%83%A9%E3%83%95)
 - [ChartJS stacked line chart](https://codepen.io/natenorberg/pen/WwqRar)
 
+### 書籍情報
 
 <div class="krb-amzlt-box" style="margin-bottom:0px;"><div class="krb-amzlt-image" style="float:left;margin:0px 12px 1px 0px;"><a href="https://www.amazon.co.jp/%E3%82%B0%E3%83%A9%E3%83%95%E3%82%92%E3%81%A4%E3%81%8F%E3%82%8B%E5%89%8D%E3%81%AB%E8%AA%AD%E3%82%80%E6%9C%AC%EF%BC%BB%E4%B8%80%E7%9E%AC%E3%81%A7%E4%BC%9D%E3%82%8F%E3%82%8B%E8%A1%A8%E7%8F%BE%E3%81%AF%E3%81%A9%E3%81%AE%E3%82%88%E3%81%86%E3%81%AB%E7%94%9F%E3%81%BE%E3%82%8C%E3%81%9F%E3%81%AE%E3%81%8B%EF%BC%BD-%E6%9D%BE%E6%9C%AC-%E5%81%A5%E5%A4%AA%E9%83%8E-ebook/dp/B075WRLPGV/ref=as_li_ss_il?__mk_ja_JP=%E3%82%AB%E3%82%BF%E3%82%AB%E3%83%8A&dchild=1&keywords=%E3%82%B0%E3%83%A9%E3%83%95%E3%82%92%E4%BD%9C%E3%82%8B%E5%89%8D%E3%81%AB&qid=1592495480&sr=8-1&linkCode=li2&tag=simsnes-22&linkId=e0d680dadb70490cd55526f37e9e4fed&language=ja_JP" target="_blank" rel="nofollow" rel="nofollow"><img border="0" src="//ws-fe.amazon-adsystem.com/widgets/q?_encoding=UTF8&ASIN=B075WRLPGV&Format= _SL250_&ID=AsinImage&MarketPlace=JP&ServiceVersion=20070822&WS=1&tag=simsnes-22&language=ja_JP" ></a><img src="https://ir-jp.amazon-adsystem.com/e/ir?t=simsnes-22&language=ja_JP&l=li2&o=9&a=B075WRLPGV" width="1" height="1" border="0" alt="" style="border:none !important; margin:0px !important;" /></div><div class="krb-amzlt-info" style="line-height:120%; margin-bottom: 10px"><div class="krb-amzlt-name" style="margin-bottom:10px;line-height:120%"><a href="https://www.amazon.co.jp/%E3%82%B0%E3%83%A9%E3%83%95%E3%82%92%E3%81%A4%E3%81%8F%E3%82%8B%E5%89%8D%E3%81%AB%E8%AA%AD%E3%82%80%E6%9C%AC%EF%BC%BB%E4%B8%80%E7%9E%AC%E3%81%A7%E4%BC%9D%E3%82%8F%E3%82%8B%E8%A1%A8%E7%8F%BE%E3%81%AF%E3%81%A9%E3%81%AE%E3%82%88%E3%81%86%E3%81%AB%E7%94%9F%E3%81%BE%E3%82%8C%E3%81%9F%E3%81%AE%E3%81%8B%EF%BC%BD-%E6%9D%BE%E6%9C%AC-%E5%81%A5%E5%A4%AA%E9%83%8E-ebook/dp/B075WRLPGV/ref=as_li_ss_il?__mk_ja_JP=%E3%82%AB%E3%82%BF%E3%82%AB%E3%83%8A&dchild=1&keywords=%E3%82%B0%E3%83%A9%E3%83%95%E3%82%92%E4%BD%9C%E3%82%8B%E5%89%8D%E3%81%AB&qid=1592495480&sr=8-1&linkCode=li2&tag=simsnes-22&linkId=e0d680dadb70490cd55526f37e9e4fed&language=ja_JP" name="amazletlink" target="_blank" rel="nofollow" rel="nofollow">グラフをつくる前に読む本［一瞬で伝わる表現はどのように生まれたのか］ Kindle版</a><div class="krb-amzlt-powered-date" style="font-size:80%;margin-top:5px;line-height:120%">posted with <a href="https://kaereba.com/wind/" title="amazlet" target="_blank" rel="nofollow" rel="nofollow">カエレバ</a></div></div><div class="krb-amzlt-detail"></div><div class="krb-amzlt-sub-info" style="float: left;"><div class="krb-amzlt-link" style="margin-top: 5px"><a href="https://www.amazon.co.jp/%E3%82%B0%E3%83%A9%E3%83%95%E3%82%92%E3%81%A4%E3%81%8F%E3%82%8B%E5%89%8D%E3%81%AB%E8%AA%AD%E3%82%80%E6%9C%AC%EF%BC%BB%E4%B8%80%E7%9E%AC%E3%81%A7%E4%BC%9D%E3%82%8F%E3%82%8B%E8%A1%A8%E7%8F%BE%E3%81%AF%E3%81%A9%E3%81%AE%E3%82%88%E3%81%86%E3%81%AB%E7%94%9F%E3%81%BE%E3%82%8C%E3%81%9F%E3%81%AE%E3%81%8B%EF%BC%BD-%E6%9D%BE%E6%9C%AC-%E5%81%A5%E5%A4%AA%E9%83%8E-ebook/dp/B075WRLPGV/ref=as_li_ss_il?__mk_ja_JP=%E3%82%AB%E3%82%BF%E3%82%AB%E3%83%8A&dchild=1&keywords=%E3%82%B0%E3%83%A9%E3%83%95%E3%82%92%E4%BD%9C%E3%82%8B%E5%89%8D%E3%81%AB&qid=1592495480&sr=8-1&linkCode=li2&tag=simsnes-22&linkId=e0d680dadb70490cd55526f37e9e4fed&language=ja_JP" name="amazletlink" target="_blank" rel="nofollow" rel="nofollow">Amazon.co.jpで詳細を見る</a></div></div></div><div class="krb-amzlt-footer" style="clear: left"></div></div>