[1] Respond to change with Object.observe - HTML5Rocks Updates ( ( 版)) <http://updates.html5rocks.com/2012/11/Respond-to-change-with-Object-observe>
[2] Chromium Blog: Chrome 36 Beta: element.animate(), HTML Imports, and Object.observe() ( ( 版)) <http://blog.chromium.org/2014/05/chrome-36-beta-elementanimate-html.html>
[3] IRC logs: freenode / #whatwg / 20140722 ( ( 版)) <http://krijnhoetmer.nl/irc-logs/whatwg/20140722>
[4] Object.observe()able properties on the web platform ( (Domenic Denicola 著, 版)) <http://lists.w3.org/Archives/Public/public-script-coord/2014JulSep/0191.html>
[5] An update on Object.observe ( 版) <https://esdiscuss.org/topic/an-update-on-object-observe>
[7] 27381 – Basing Object.observe() for IDL objects on internal slots ( ()) <https://www.w3.org/Bugs/Public/show_bug.cgi?id=27381>
[8] s/filter/remove unsupported types (igrigorik著, ) <https://github.com/w3c/performance-timeline/commit/74a9181d8ac1bfb5410b1f57c94a8d28b11911ed>
[9] Step 1 of "observe" is not clear · Issue #89 · w3c/performance-timeline () <https://github.com/w3c/performance-timeline/issues/89>