Carolyn Gordon et David Webb, « You can't hear the shape of a drum », American Scientist, vol. 84, no January-February, , p. 46-55
C. Gordon, D. Webb et S. Wolpert, « Isospectral plane domains and surfaces via Riemannian orbifolds », Inventiones Mathematicae, vol. 110, , p. 1-22 (DOI10.1007/BF01231320)
Carolyn Gordon, David Webb et Scott Wolpert, « One Cannot Hear the Shape of a Drum », Bulletin of the American Mathematical Society, vol. 27, , p. 134-138 (DOI10.1090/S0273-0979-1992-00289-6, lire en ligne)