Ashraf, M. M., Ullah, M. O., Malik, T. N., Waqas, A. B., Iqbal, M. and Siddiq, F. (2018) “Robust Extraction of Harmonics using Heuristic Advanced Gravitational Search Algorithm-based Least Square Estimator”, The Nucleus, 54(4), pp. 219–231. doi: 10.71330/thenucleus.2017.273.