Fatemeh, D. B., C. K. Loo, G. Kanagaraj, and S. G. Ponnambalam. “A Hybrid SP-QPSO Algorithm With Parameter Free Adaptive Penalty Method for Constrained Global Optimization Problems”. Journal of Modern Manufacturing Systems and Technology, vol. 1, Sept. 2018, pp. 15-26, doi:10.15282/jmmst.v1i1.195.