Looking for logging into the Google Sites Sign In site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Google Sites Sign In site. After that you can login as usual with your login credentials.
https://sites.google.com/
https://www.google.com/a/UniversalLogin
https://chrome.google.com/webstore/detail/google-sites/gmandedkgonhldbnjpikffdnneenijnd
https://qiita.com/hasoya/items/e69d01d339ef831d25dd
https://support.google.com/a/answer/1751957?hl=ja
https://support.google.com/a/answer/7392423?hl=ja
https://support.google.com/a/answer/90915?hl=ja
https://productforums.google.com/d/msg/sites/LOCQi9z2L6I/nNr4MDB4BgAJ
http://caenfaq.engin.umich.edu/google-sites/how-do-i-access-my-site-to-start-editing-it-gs
https://gsuite.google.com/learning-center/products/sites/get-started/
https://www.lynda.com/Google-Sites-tutorials/Accessing-Google-Sites-your-Google-account/153986/163699-4.html
https://developers.google.com/identity/sign-in/web/
https://developers.google.com/sites/gadgets/site_gadgets