EN
EN
RU
×
EN
EN
RU
×
Main menu
Main menu
move to sidebar
hide
Navigation
Main page
Contents
Current events
Random article
About Wikipedia
Contact us
Donate
Contribute
Help
Learn to edit
Community portal
Recent changes
Upload file
Search
Search
Appearance
Create account
Log in
Personal tools
Create account
Log in
Pages for logged out editors
learn more
Contributions
Talk
File talk
:
Toolbar insert reference.png
Add languages
Page contents not supported in other languages.
File
Talk
English
Read
Edit
Add topic
View history
Tools
Tools
move to sidebar
hide
Actions
Read
Edit
Add topic
View history
General
What links here
Related changes
Upload file
Special pages
Permanent link
Page information
Get shortened URL
Download QR code
Print/export
Download as PDF
Printable version
Appearance
move to sidebar
hide
Source: Wikipedia, the free encyclopedia.
[1]
^
Gnawledge, O'penn. "Planet Earth in the Balance of History". Science and Nature Journal. SandNjournal.com/Earthinthebalance. March 21, 2013. Retrieved 14:55, Monday, December 26, 2016 (UTC).
