use the following search parameters to narrow your results:
e.g. subreddit:pics site:imgur.com dog
subreddit:pics site:imgur.com dog
advanced search: by author, sub...
~5 users here now
Digon
submitted 3 years ago by [deleted] from en.wikipedia.org
Hadwiger conjecture
Four color theorem
Glossary of graph theory terms
Five color theorem
Graph (Topology)
Graph (discrete mathematics)