[1] Creative Commons — Attribution-ShareAlike 3.0 Unported — CC BY-SA 3.0 ( ( 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 ( ( 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 ( ( 版)) https://creativecommons.org/weblog/entry/44030