NAZAROV, Sergey A.; TASKINEN, Jari. On essential and continuous spectra of the linearized water-wave problem in a finite pond. Mathematica Scandinavica, Berkeley, CA, United States, v. 106, n. 1, p. 141–160, 2010. DOI: 10.7146/math.scand.a-15129. Disponível em: https://journals.msp.org/mscand/article/view/568. Acesso em: 24 jul. 2026.