[1] window.event and Event.srcElement ( (Anne van Kesteren 著, 2013-03-25 22:44:19 +09:00 版)) http://lists.w3.org/Archives/Public/public-webapps/2013JanMar/0961.html

[2] Bug 20713 – Consider defining window.event and Event.srcElement (2015-07-07 11:47:22 +09:00 版) https://www.w3.org/Bugs/Public/show_bug.cgi?id=20713

[3] 453968 – Support IE extension Event.srcElement (2015-07-07 11:47:34 +09:00 版) https://bugzilla.mozilla.org/show_bug.cgi?id=453968

[4] Define Event.srcElement and Event.returnValue · Issue #625 · whatwg/dom (2018-04-10 22:46:35 +09:00) https://github.com/whatwg/dom/issues/625

[5] Define Event.srcElement and Event.returnValue by miketaylr · Pull Request #626 · whatwg/dom (2018-04-10 22:47:00 +09:00) https://github.com/whatwg/dom/pull/626