HYLLERAAS, Egil A. Linearization of Products of Jacobi Polynomials. Mathematica Scandinavica, Berkeley, CA, United States, v. 10, p. 189–200, 1962. DOI: 10.7146/math.scand.a-10527. Disponível em: https://journals.msp.org/mscand/article/view/2662. Acesso em: 25 jul. 2026.