P. Kiatsookkanatorn, P. Klamrak, N. Yindeeyom, and N. Watjanatepin, “Investigation of the Effect of Harmonic Currents on Losses of Phase Shifting Transformers and Its Realization using a 15-Degree Phase shifting Transformer”, RMUTP Research Journal, vol. 16, no. 2, pp. 113–126, Dec. 2022.