RESSEL, P.; RICKER, W. J. Vector-valued positive definite functions, the Berg-Maserick theorem, and applications. MATHEMATICA SCANDINAVICA, [S. l.], v. 90, n. 2, p. 289–319, 2002. DOI: 10.7146/math.scand.a-14375. Disponível em: https://www.mscand.dk/article/view/14375. Acesso em: 3 may. 2024.