Othman, Mahmoud M., Yasser G. Hegazy, and Almoataz Y. Abdelaziz. 2015. “A Modified Firefly Algorithm for Optimal Sizing and Siting of Voltage Controlled Distributed Generators in Distribution Networks”. Periodica Polytechnica Electrical Engineering and Computer Science 59 (3):104-9. https://doi.org/10.3311/PPee.8579.