1. Abramowitz, M., Stegun, I.A. (1978): Handbook of mathematical functions. Dover, New York
2. Elbert, �., Laforgia, A. (1985): On the convexity of the zeros of Bessel functions. SIAM J. Math. Anal. Appl.16, 614?619
3. Elbert, �., Laforgia, A. (1984): An asymptotic relation for the zeros of Bessel functions. J. Math. Anal. Appl.98, 502?511
4. Elbert, �., Laforgia, A., Lorch, L.: Additional monotonicity properties of the zeros of Bessel functions. Analysis (to appear)
5. Watson, G.N. (1944): A treatise on the theory of Bessel functions, 2nd ed. Cambridge Univ. Press, London New York