[1] [CITE@en-US[SafeFrame]]
([TIME[2017-06-15 15:33:23 +09:00]])
<https://www.iab.com/guidelines/safeframe/>

[2] ([TIME[2017-01-25 12:04:23 +09:00]])
<http://www.iab.com/wp-content/uploads/2014/08/SafeFrames_v1.1_final.pdf>