Giraldo, L. C., J. J. Mora, and G. Olguin. “Evaluation of the Stator Ground-Fault Protection for Synchronous Generators by Means of the Subharmonic Injection Method”. Ingeniería Y Competitividad, vol. 10, no. 1, Jan. 2008, pp. 21-30, doi:10.25100/iyc.v10i1.2478.