Who is the owner of this information?

The tilde ( ~ ) indicates the file is in ~vattulai's personal folder. Truncating the URL back to http://www.helsinki.fi/~vattulai/ reveals the owner's full name: Ilpo Vattulainen

Is this information live or archived?

The presence the word cache in this address is one clue that it is archived. Another is the reference to wikipedia in the URL. This is a copy of the last wikipedia page to be archived on this topic by Yahoo.

Who else references this document?

When Mutsumi Suzuki retired from Tohoku University in 2001, he removed files from his personal folder. A number of others valued his work and copies of his work can be found on their Web pages. This particular file may be found in Google on this page: http://www.genealogy.com/users/d/e/f/Antonio-D-De-figueiredo/FILE/0011page.html. While at first it looks like a blank page, use the Find command to search for the term magicsquare or Suzuki (you know it's supposed to be there). From there you have to be able to read Spanish. See if you can use clues on this page to find an English explanation of these magic squares and who actually created them