[1] [CITE@en[(X)HTML5 Tracking]]
([TIME[2009-10-23 23:16:19 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=4272&to=4273>

[2] [CITE[''''''[''''''whatwg'''''']'''''' Recursion and loops of Microdata items]]
( ([TIME[2011-06-09 08:32:45 +09:00]] 版))
<http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2011-June/031965.html>