  Spherical Bessel functions appear commonly in many areas of physics wherein
there is both translation and rotation invariance, and often integrals over
products of several arise. Thus, analytic evaluation of such integrals with
different weighting functions (which appear as toy models of a given physical
observable, such as the galaxy power spectrum) is useful. Here we present a
generalization of a recursion-based method for evaluating such integrals. It
gives relatively simple closed-form results in terms of Legendre functions (for
the exponentially-damped case) and Gamma, incomplete Gamma functions, and
hypergeometric functions (for the Gaussian-damped case). We also present a new,
non-recursive method to evaluate integrals of products of spherical Bessel
functions with Gaussian damping in terms of incomplete Gamma functions and
hypergeometric functions.
