ANDERSEN, Erik Sparre. Two summation formulae for product sums of binomial coefficients. MATHEMATICA SCANDINAVICA, [S. l.], v. 1, p. 261–262, 1953. DOI: 10.7146/math.scand.a-10384. Disponível em: https://tidsskrift.dk/math/article/view/10384. Acesso em: 14 aug. 2026.