HAVNEN, Johan. Completely Monotonic Functions on $n$-Dimensional Lattices. MATHEMATICA SCANDINAVICA, [S. l.], v. 33, p. 314–322, 1973. DOI: 10.7146/math.scand.a-11493. Disponível em: https://tidsskrift.dk/math/article/view/11493. Acesso em: 13 aug. 2026.