[1] [CITE@en[Cascading Style Sheets (CSS) Snapshot 2010]]
( ([TIME[2010-12-07 23:22:27 +09:00]] 版))
<http://www.w3.org/TR/2010/WD-css-2010-20101202/>

[2] [CITE@en[Cascading Style Sheets (CSS) Snapshot 2010]]
( ([TIME[2011-05-12 23:24:12 +09:00]] 版))
<http://www.w3.org/TR/2011/NOTE-css-2010-20110512/>