[1] M. Abramowitz, I. A. Stegun, eds.: Handbook of Mathematical Functions. Applied Mathematics Series, vol. 55, National Bureau of Standards, Washington, 1964. Zbl 0171.38503

[2] S. Ahmed aпd F. Calogero: On the zeros of Bessel Functions. - III. Lett. Nuovo Cimento, 21 (1978), 311-314. MR 0496061

[3] J. R. Airey: The vibrations of cylinders and cylindrical shells. Arch. d. Math. u. Phys. (3) 20 (1913), 289-294.

[4] H. S. Carslaw, J. C. Jaeger: Conduction of heat in solids. 2nd ed., Clarendon Press, Oxford, 1959. MR 0959730

[5] R. Couгant, D. Hilbert: The methods of mathematical physics. vol. 1, 1st English edition, Wiley-Interscience, New York, 1953. MR 0065391

[6] A. Erdélyi, al.: Higher transcendental functions. vol. 2, McGгaw-Hill, New Yoгk, 1954.

[7] K. D. Graham: Separation of eigenvalues of the wave equation for the unit ball in $R^N$. Studies Appl. Math. 52 (1973), 329-343. MR 0377257

[8] K. D. Graham: On boundary value control of symmetric hyperbotic systems. Ph. D thesis, University of Minnesota, Minneapolis, 1973.

[9] K. D. Graham, D. L. Russell: Boundary value control of the wave equation in a spherical region. SIAM. J. Control 13 (1975), 174-196. MR 0355756 | Zbl 0315.93004

[10] P. Hartman, A. Wintner: On nonconservative linear oscillators of low frequency. Amer. J. Math. 70 (1945), 529-539. MR 0026736

[11] M. E. H. Ismail, M. E. Muldoon: Monotonicity of the zeros of a cross-product of Bessel functions. SIAM. J. Math. Anal. 9 (1978), 759-767. MR 0486686 | Zbl 0388.33005

[12] E. Jähnke F. Emde, F. Lösch: Tables of higher functions. 6th ed., McGraw-Hill, New York, 1960. MR 0114317

[13] K. Kreith: Comparison theorems for non-self-adjoint differential equations based on integral inequalities. Proc. Amer. Math. Soc. 34 (1972), 105-109. MR 0304770

[14] W. Leighton: A substitute for the Picone formula. Bull. Amer. Math. Soc. 55 (1949), 325-328. MR 0031156 | Zbl 0032.34702

[15] W. Leighton: Comparison theorems for linear differential equations of the second order. Proc. Amer. Math. Soc. 13 (1962), 603-610. MR 0140759

[16] A. Yu. Levin: A comparison principle for second-order differential equations. Soviet Math. Doklady 1 (1960), 1313-1316. [Russian original, Dokl. Akad. Nauk SSSR 136 (1960), 783-786.] MR 0124563 | Zbl 0102.07801

[17] J. T. Lewis, M. E. Muldoon: Monotonicity and convexity properties of zeros of Bessel functions. SIAM. J. Math. Anal. 8 (1977), 171-178. MR 0437823 | Zbl 0365.33004

[18] L. Lorch: Comparison of two formulations of Sonin's theorem and of their respective applications to Bessel functions. Studia Sci. Math. Hungar. 1 (1966), 141-145. MR 0204723 | Zbl 0148.30101

[19] L. Lorch M. E. Muldoon, P. Szego: Higher monotonicity properties of certain Sturm-Liouville functions, IV. Canad. J. Math. 24 (1972), 349-365. MR 0298113

[20] E. Makai: On a monotonic property of certain Sturm-Liouville functions. Acta. Math. Acad. Sci. Hungar. 3 (1952), 165-172. MR 0054103 | Zbl 0048.32302

[21] M. E. Muldoon: On the zeros of a cross-product of Bessel functions of different orders. Z. Angew. Math. Mech., 59 (1979), 272-273. MR 0545781 | Zbl 0409.33007

[22] A. D. Rawlins: A new class of Bessel function inequality useful for investigating the roots of a class of transcendental equation involving Bessel functions. Proc. Roy. Soc. Edinburgh 74A (1974-1975), 231-238. MR 0440089

[23] R. Ruedy: On the propagation of longitudinal waves in cylindrical rods. Canad. J. Research, 5 (1931), 149-155.

[24] R. Spigler: Sulle radici dell' equazione: $A J_v(x) + Bx J'_v(x) = 0$. Atti Sem. Mat. Fis. Univ. Modena 24 (1975), 399-419. MR 0422723

[25] Ch. Sturm: Mémoire sur les équations différentielles du second ordre. J. Math. Pures Appl. 1 (1836), 106-186.

[26] G. Szegö: Inequalities for the zeros of Legendre polynomials and related functions. Trans. Amer. Math. Soc. 39 (1936), 1-17. MR 1501831

[27] G. Szegö: Orhogonal polynomials. Amer. Math. Soc. Colloquium Publications, vol. 23,4th ed., 1975.

[28] G. N. Watson: A treatise on the theory of Bessel functions. 2nd ed., Cambridge University Press, 1944. MR 0010746 | Zbl 0063.08184