LI, Fengling; LEI, Fengchun; YANG, Guoqiu. Some Sufficient Conditions for Heegaard Genera to Be Additive Under Annulus Sum. Mathematica Scandinavica, Berkeley, CA, United States, v. 115, n. 2, p. 173–188, 2014. DOI: 10.7146/math.scand.a-19221. Disponível em: https://journals.msp.org/mscand/article/view/409. Acesso em: 24 jul. 2026.