Bhumika Sahu, MPS Chawla, and Sandeep Bhongade. “Optimization of PID Controller for a Hybrid Power System Using Particle Swarm Optimization Technique”. Journal of Power Electronics and Devices, vol. 3, no. 3, Dec. 2018, pp. 22-33, http://matjournals.co.in/index.php/JOPED/article/view/6496.