Feature comparison
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Strengths/Focus |
mainly Arts & Humanities |
Sciences |
Physics, Mathematics, Computer Science, Nonlinear Sciences, Quantitative Biology and Statistics |
It's up to you |
|
Sign in/Link with Facebook? |
Yes |
Yes |
No |
No |
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Cost |
Free |
Free |
Free |
Free |
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Mobile |
No |
No |
No |
No |
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Tagging/Following |
Yes |
Yes |
Yes |
Yes |
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Year launched |
2008 |
2008 |
1991 |
2011 (?) |
|
Current membership |
2,626,807 |
2.7 million | 7+ million (?) | could not verify |
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Number of documents |
1,649,326 |
10+ million | 837,694 | could not verify |
