GUTMAN, Ivan. On the sum of powers of vertex degrees of polycyclic graphs. Vojnotehnički glasnik / Military Technical Courier, [S. l.], v. 73, n. 3, p. 727–735, 2025. DOI: 10.5937/vojtehg73-61342. Dostupno na: https://asistent.ceon.rs/index.php/vtg/article/view/61342. Pristupljeno: 12 jul. 2026.