[1] CSS Values and Units Module Level 3 ( (2015-06-11 05:29:20 +09:00 版)) http://www.w3.org/TR/2015/CR-css-values-3-20150611/

[2] Re: [css3-values][css3-speech] dB & calc() ( (Tab Atkins Jr.著, 2016-05-10 01:18:25 +09:00)) https://lists.w3.org/Archives/Public/www-style/2016May/0083.html

[3] CSS Values and Units Module Level 3 (2016-09-29 22:15:07 +09:00) https://www.w3.org/TR/2016/CR-css-values-3-20160929/

[4] [CSSWG][css-values-3] Updated CR of CSS Values and Units Level 3 (fantasai著, 2018-08-15 08:47:11 +09:00) https://lists.w3.org/Archives/Public/www-style/2018Aug/0013.html

[5] [CSSWG][css-values-4] FPWD of CSS Values and Units Level 4 (fantasai著, 2018-08-15 08:55:44 +09:00) https://lists.w3.org/Archives/Public/www-style/2018Aug/0014.html