[1] [CITE@en[CSS Values and Units Module Level 3]]
( ([TIME[2011-09-06 17:51:33 +09:00]] 版))
[2] [CITE@en[CSS Values and Units Module Level 3]]
( ([TIME[2012-03-08 22:56:28 +09:00]] 版))
[3] [CITE@en[CSS Values and Units Module Level 3]]
( ([TIME[2012-08-28 00:22:41 +09:00]] 版))
[4] [CITE@en[CSS Values and Units Module Level 3]]
( ([TIME[2013-04-04 00:50:56 +09:00]] 版))