Remove extra citations

This commit is contained in:
Antti H S Laaksonen 2017-02-22 21:44:42 +02:00
parent 2784ffa5ee
commit b12d09ee6c
2 changed files with 3 additions and 7 deletions

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@ -546,4 +546,4 @@ it is difficult to find out if the nodes
in a graph can be colored using $k$ colors
so that no adjacent nodes have the same color.
Even when $k=3$, no efficient algorithm is known
but the problem is NP-hard \cite{gar79}.
but the problem is NP-hard.