Dear Sirs, there is a misprint in Irregular Spherical Bessel Functions Function: int gsl_sf_bessel_y2_e (double x, gsl_sf_result * result) These routines compute the irregular spherical Bessel function of second order, y_2(x) = (-3/x^2 + 1/x)\cos(x) - (3/x^2)\sin(x). becomes y_2(x) = (-3/x^3 + 1/x)\cos(x) - (3/x^2)\sin(x). Best Regards Mario Pernici