Update README.md

Author: Evolutionary-Intelligence

README.md

@@ -553,7 +553,7 @@ reported in the (actively-updated) paper list called
 [DistributedEvolutionaryComputation](https://github.com/Evolutionary-Intelligence/DistributedEvolutionaryComputation).
 
 * **Derivative-Free Optimization (DFO) / Zeroth-Order Optimization (ZOO)**
-  * [Berahas](), et al., 2022.
+  * [Berahas](https://aberahas.engin.umich.edu), et al., 2022.
     [A theoretical and empirical comparison of gradient approximations in
     derivative-free optimization](https://link.springer.com/article/10.1007/s10208-021-09513-z).
     FoCM, 22(2), pp.507-560.