[1] Creative Commons — Attribution-ShareAlike 3.0 Unported — CC BY-SA 3.0 ( (2014-09-03 07:02:58 +09:00 版)) https://creativecommons.org/licenses/by-sa/3.0/deed

[2] Creative Commons — 表示 - 継承 4.0 国際 — CC BY-SA 4.0 ( (2014-11-03 08:59:07 +09:00 版)) https://creativecommons.org/licenses/by-sa/4.0/deed.ja

[3] Big win for an interoperable commons: BY-SA and FAL now compatible - Creative Commons ( (2014-11-03 09:09:01 +09:00 版)) https://creativecommons.org/weblog/entry/44030