OTTEM, J. C. On the Cox ring of $\mathbf{P}^2$ blown up in points on a line. MATHEMATICA SCANDINAVICA, [S. l.], v. 109, n. 1, p. 22–30, 2011. DOI: 10.7146/math.scand.a-15175. Disponível em: https://www.mscand.dk/article/view/15175. Acesso em: 2 may. 2024.