KALFAKAKOU, R.; NIKOLAKOPOULOU, G.; SAVVIDOU, E.; TSOUROS, M. Graph radio coloring concepts. Yugoslav Journal of Operations Research, [S. l.], v. 13, n. 2, p. 207–215, 2003. DOI: 10.2298/YJOR0302207K. Disponível em: https://yujor.erc.fon.bg.ac.rs/index.php/yujor/article/view/94. Acesso em: 21 jan. 2026.