Tài liệu tham khảo WikiPedia: Dropbox http://ftp-master.metadata.debian.org/changelogs//... https://www.alexa.com/siteinfo/dropbox.com https://www.dropbox.com/ https://www.dropbox.com/about https://web.archive.org/web/20131029201646/http://... https://commons.wikimedia.org/wiki/Category:Dropbo...
