BENJAMIN, Elliot; SNYDER, C. Real Quadratic Number Fields with 2-Class Group of Type (2,2). MATHEMATICA SCANDINAVICA, [S. l.], v. 76, p. 161–178, 1995. DOI: 10.7146/math.scand.a-12532. Disponível em: https://www.mscand.dk/article/view/12532. Acesso em: 5 dec. 2025.