DIMITROV, D. T.; RALEV, N. D. Signals and Systems for Electrosleep. Elektronika ir Elektrotechnika, [S. l.], v. 93, n. 5, p. 95-98, 2009. Disponível em: https://eejournal.ktu.lt/index.php/elt/article/view/10191. Acesso em: 25 sep. 2020.