KHACHATRYAN, H.H. DEFICIENCY OF OUTERPLANAR GRAPHS. Proceedings of the YSU A: Physical and Mathematical Sciences, Yerevan, Armenia, v. 51, n. 1 (242), p. 22–28, 2017. DOI: 10.46991/PYSU:A/2017.51.1.022. Disponível em: https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol51_no1_2017_pp022-028. Acesso em: 22 jul. 2024.