Some planar isospectral domains

`Some planar isospectral domains', by Peter Buser, John Conway, Peter Doyle, and Klaus-Dieter Semmler:

• Hypertext version
• Postscript version
• Mathematica notebook of figures

• Buser's isospectral art gallery
• Examples with topology (size 11 pairs)
• Examples with topology (size 21 pairs)