WANG, C. Y. Biharmonic Green’s functions and biharmonic degeneracy. Mathematica Scandinavica, Berkeley, CA, United States, v. 37, p. 122–128, 1975. DOI: 10.7146/math.scand.a-11594. Disponível em: https://journals.msp.org/mscand/article/view/2075. Acesso em: 25 jul. 2026.