WAGNER, Peter. A Fundamental Solution of N. Zeilon’s Operator. Mathematica Scandinavica, Berkeley, CA, United States, v. 86, n. 2, p. 273–287, 2000. DOI: 10.7146/math.scand.a-14293. Disponível em: https://journals.msp.org/mscand/article/view/912. Acesso em: 25 jul. 2026.