Mata Zamora, M. E., B. Valera Orozco, and H. Montiel. “Determination of Initial Permeability in Soft Ferrites With the Modified Rowland’s Ring Method”. Superficies Y Vacío, vol. 25, no. 2, June 2012, pp. 122-7, https://superficiesyvacio.smctsm.org.mx/index.php/SyV/article/view/216.