[1] [CITE@en[Compound Document by Reference Framework 1.0]]
( ([TIME[2010-08-17 16:50:04 +09:00]] 版))
<http://www.w3.org/TR/CDR/#parent-to-child-dom-access>

[2] [CITE@en-US-x-hixie[HTML Standard]]
( ([TIME[2012-12-05 05:38:42 +09:00]] 版))
<http://www.whatwg.org/specs/web-apps/current-work/#dom-iframe-contentdocument>