[5] Google, 2024-08-24T08:20:21.000Z, 2011-06-03T15:37:47.880Z https://web.archive.org/web/20110603153735/http://www.google.com/intl/ja/webmasters/+1/button/

[2] Markup | 2019 | The Web Almanac by HTTP Archive, 2024-08-24T08:18:50.000Z https://almanac.httparchive.org/en/2019/markup

[3] Add +1 to help your site stand out | Google Search Central Blog | Google for Developers, 2011-06-01T07:00:00.000Z, 2024-08-24T08:19:25.122Z https://developers.google.com/search/blog/2011/06/add-1-to-help-your-site-stand-out

[4] +1 ボタンが日本のウェブマスターの皆さまにもご利用頂けるようになりました | Google 検索セントラル ブログ | Google for Developers, 2011-06-01T07:00:00.000Z, 2024-08-24T08:19:41.035Z https://developers.google.com/search/blog/2011/06/1?hl=ja

[1] Googleが「+1」(プラスワン)ボタンを一般公開, 2024-08-24T08:18:29.000Z https://www.suzukikenichi.com/blog/you-can-get-google-plus-one-button-now/

[6] Google +1 ボタンを表示する - DoboWiki, 2024-08-24T08:21:05.000Z https://wiki.dobon.net/index.php?ShareButton%2FGoogle%2B1