[1] [CITE@en-US[x-callback-url Support – Contrast Tech Support]]
( ([TIME[2013-11-16 04:03:50 +09:00]] 版))
<http://help.contrast.co/hc/en-us/articles/200611883-x-callback-url-Support>

[2] [CITE@en-US[Dropbox Actions – Contrast Tech Support]]
( ([TIME[2013-11-16 04:05:31 +09:00]] 版))
<http://help.contrast.co/hc/en-us/articles/200612283-Dropbox-Actions>