[1] Extend Metadata - CC Wiki ( (2014-05-09 20:08:24 +09:00 版)) <http://wiki.creativecommons.org/Extend_Metadata>

[2] Extending Creative Commons Metadata | Creative Commons ( (2014-05-23 04:17:17 +09:00 版)) <http://web.archive.org/web/20041210110048/http://creativecommons.org/technology/metadata/extend>