Novakovic, I. M., S. R. Aleksic, and N. B. Raicevic. “New Hybrid EEM/BEM Method for Ellipsoidal Electrets Determination”. Elektronika Ir Elektrotechnika, vol. 19, no. 3, Jan. 2013, pp. 11-16, doi:10.5755/j01.eee.19.3.3217.