Update references

Author: firefly-cpp

README.md

@@ -122,10 +122,12 @@ options:
 
 ## 📚 Reference Papers
 
-I. Fister Jr.,  X.-S. Yang,  I. Fister, J. Brest. [Memetic firefly algorithm for combinatorial optimization](http://www.iztok-jr-fister.eu/static/publications/44.pdf) in Bioinspired Optimization Methods and their Applications (BIOMA 2012), B. Filipic and J.Silc, Eds.
+I. Fister Jr., X.-S. Yang, I. Fister, J. Brest, D. Fister. [A Brief Review of Nature-Inspired Algorithms for Optimization](http://www.iztok-jr-fister.eu/static/publications/21.pdf). Elektrotehniški vestnik, 80(3), 116-122, 2013.
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+I. Fister Jr., X.-S. Yang, I. Fister, J. Brest. [Memetic firefly algorithm for combinatorial optimization](http://www.iztok-jr-fister.eu/static/publications/44.pdf) in Bioinspired Optimization Methods and their Applications (BIOMA 2012), B. Filipic and J.Silc, Eds.
 Jozef Stefan Institute, Ljubljana, Slovenia, 2012
 
-I. Fister, I. Fister Jr.,  X.-S. Yang, J. Brest. [A comprehensive review of firefly algorithms](http://www.iztok-jr-fister.eu/static/publications/23.pdf). Swarm and Evolutionary Computation 13 (2013): 34-46.
+I. Fister, I. Fister Jr., X.-S. Yang, J. Brest. [A comprehensive review of firefly algorithms](http://www.iztok-jr-fister.eu/static/publications/23.pdf). Swarm and Evolutionary Computation 13 (2013): 34-46.
 
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