NAKAI, Mitsuru; SARIO, Leo. A nonexistence test for biharmonic Green’s functions of clamped bodies. Mathematica Scandinavica, Berkeley, CA, United States, v. 40, p. 151–160, 1977. DOI: 10.7146/math.scand.a-11684. Disponível em: https://journals.msp.org/mscand/article/view/1959. Acesso em: 25 jul. 2026.