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2. The zeros of Hankel functions as functions of their order;Alan Cochran;Numer. Math.,1965
3. Sur les zéros des fonctions de Bessel considérées comme fonction de l’ordre;Coulomb;Bull. Sci. Math.,1936
4. The roots of trigonometric integrals;de Bruijn;Duke Math. J.,1950
5. Bessel functions of purely imaginary order, with an application to second-order linear differential equations having a large parameter;Dunster;SIAM J. Math. Anal.,1990