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http://drive.google.com/
(accessed April 10, 2014)
2. Onedrive,
https://onedrive.live.com/about/en-us/
(accessed April 10, 2014)
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http://www.pleasetech.com/pleasereview.aspx/
(accessed April 10, 2014)
4. Ubuntu one,
https://one.ubuntu.com/
(accessed April 10, 2014)
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