A general procedure for the calculation of a class of two-loop Feynman
diagrams is described. These are two-point functions containing three massive
propagators, raised to integer powers, in the denominator, and arbitrary
polynomials of the loop momenta in the numerator. The ultraviolet divergent
parts are calculated analytically, while the remaining finite parts are
obtained by a one-dimensional numerical integration, both below and above the
threshold. Integrals of this type occur, for example, in chiral perturbation
theory at order p^6.Comment: 13 pages, LATEX, 2 LATEX figure