GULLIKSEN, Tor H. A Change of Ring Theorem with Applications to Poincaré Series and Intersection Multiplicity. Mathematica Scandinavica, Berkeley, CA, United States, v. 34, p. 167–183, 1974. DOI: 10.7146/math.scand.a-11518. Disponível em: https://journals.msp.org/mscand/article/view/2128. Acesso em: 25 jul. 2026.