Merge pull request #1291 from Axelrod-Python/docs-fix

Docs fix

Author: Nikoleta-v3

docs/reference/overview_of_strategies.rst

@@ -165,7 +165,7 @@ ALLC, ALLD, TFT and RANDOM are defined above. The remaining classical
 strategies are defined below. The tournament also included two Zero Determinant
 strategies, both implemented in the library. The full table of strategies and
 results is `available
-online <http://www.pnas.org/content/109/26/10134/F1.expansion.html>`_.
+online <https://www.pnas.org/content/pnas/109/26/10134/F1.large.jpg?width=800&height=600&carousel=1>`_.
 
 Memory one strategies
 ^^^^^^^^^^^^^^^^^^^^^
@@ -301,7 +301,7 @@ HARD_TFT
 ^^^^^^^^
 
 Hard TFT is not defined in [Stewart2012]_ but is
-`[elsewhere] <http://www.prisoners-dilemma.com/strategies.html>`_
+`elsewhere <http://www.prisoners-dilemma.com/strategies.html>`_
 defined as follows. The strategy cooperates on the
 first move, defects if the opponent has defected on any of the previous three
 rounds, and otherwise cooperates.