WILLIAMS, Kenneth S. Forms Representable by an Integral Positive-Definite Binary Quadratic Form. Mathematica Scandinavica, Berkeley, CA, United States, v. 29, p. 73–86, 1971. DOI: 10.7146/math.scand.a-11036. Disponível em: https://journals.msp.org/mscand/article/view/2319. Acesso em: 25 jul. 2026.