[1] [CITE@en-GB-x-Hixie[Web Forms 2.0]]
([TIME[2009-01-05 20:07:15 +09:00]] 版)
<http://www.whatwg.org/specs/web-forms/current-work/#selectedindex>

[2] [CITE@@en[Web Applications 1.0 r5439     HTMLOptionsCollection.selectedItemFixing http://www.w3.org/Bugs/Public/show_bug.cgi?id=10184]]
( ([TIME[2010-09-08 14:16:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=5438&to=5439>