RITONJA, J.; PETRUN, M.; CERNELIC, J.; BREZOVNIK, R.; POLAJZER, B. Analysis and Applicability of Heffron–Phillips Model. Elektronika ir Elektrotechnika, [S. l.], v. 22, n. 4, p. 3 - 10, 2016. DOI: 10.5755/j01.eie.22.4.15905. Disponível em: https://eejournal.ktu.lt/index.php/elt/article/view/15905. Acesso em: 29 mar. 2024.