VRETARE, Lars. Elementary spherical functions on symmetric spaces. Mathematica Scandinavica, Berkeley, CA, United States, v. 39, p. 343–358, 1976. DOI: 10.7146/math.scand.a-11667. Disponível em: https://journals.msp.org/mscand/article/view/1978. Acesso em: 25 jul. 2026.