Dimitrov, D. T., and A. D. Dimitrov. “Space-Temporal Processing of Low Frequency Electric and Magnetic Signals in a Linear Medium-Analysis and Application in Medical Therapy”. Elektronika Ir Elektrotechnika, vol. 20, no. 1, Jan. 2014, pp. 67-70, doi:10.5755/j01.eee.20.1.3292.