SOMSRI, B.; PIPATTANAJINDA, N. The Number of Endomorphism of Barbell Graphs. Journal of Science and Technology CRRU, Chiangrai, Thailand, v. 4, n. 2, p. 61–70, 2025. Disponível em: https://li01.tci-thaijo.org/index.php/jstcrru/article/view/267592. Acesso em: 16 sep. 2026.