1. The Theory of Sound;RAYLEIGH,1945
2. On the polygonal membrane with a circular core;WANG;Journal of Sound and Vibration,1998
3. Integer Order, Chapter 9;OLVER,1972
4. Handbook of Mathematical Formulas and Integrals;JEFFREY,1995
5. P. M. MORSE, 1983, Vibration and Sound, American Institute of Physics reprint; second edition, 1948