Ahmad, M.A., Raja Ismail, R.M.T., Suid, M.H., Mat Jusof, M.F., Musa, Z., Mustapha, N.M.Z.A. and Ghazali, M.R. 2018. A Model-free Approach to Optimal Chiller Loading Problem Using Global Simultaneous Perturbation Stochastic Approximation. Journal of Telecommunication, Electronic and Computer Engineering (JTEC). 10, 1-3 (Jan. 2018), 45–50.