[1] ドラッグによるテキストの選択をキャンセルする【CSS, HTML, JavaScript】 - Programming Magic ( ( 版)) <http://www.programming-magic.com/20071217225449/>
[2] User Interface Enhancements ( ( 版)) <http://www.w3.org/TR/1999/WD-css3-userint-19990916#user-select>
[3] User Interface for CSS3 ( ( 版)) <http://www.w3.org/TR/2000/WD-css3-userint-20000216#user-select>
[4] Specifying selectable text (Windows) ( ( 版)) <http://msdn.microsoft.com/en-us/library/ie/hh708742(v=vs.85).aspx>
[5] IRC logs: freenode / #whatwg / 20150601 ( 版) <http://krijnhoetmer.nl/irc-logs/whatwg/20150601>
[6] -webkit-user-select: text;
[7] -webkit-user-select: ignore
[8] Fixes #37. Add -webkit-user-select prefixed property alias. · whatwg/compat@49fb0fb ( 版) <https://github.com/whatwg/compat/commit/49fb0fb55c9c866df8d2b521b634009b21b03a22>
[9] [css-ui-4] -webkit-user-select (Florian Rivoal 著, 版) <https://lists.w3.org/Archives/Public/www-style/2016Feb/0050.html>
[10] [css-ui-4] aliasing of -webkit-user-select · w3c/csswg-drafts@dfde9cf ( 版) <https://github.com/w3c/csswg-drafts/commit/dfde9cf322831e1bc0d1385e6df68057adc08ec6>
[11] Fixes #49. Remove -webkit-user-select alias. · whatwg/compat@a1c9eed ( 版) <https://github.com/whatwg/compat/commit/a1c9eed977cfdda1830d79636d22bb9e9ab1eca4>
[12] [css-ui] Add note about excessive use of user-select:none (frivoal著, ) <https://github.com/w3c/csswg-drafts/commit/016920866197fe3a8fd0e23ce9d062358fcae49b>