  Recently, algorithms for calculation of 3-loop propagator diagrams in HQET
and on-shell QCD with a heavy quark have been constructed and implemented.
These algorithms (based on integration by parts recurrence relations) reduce an
arbitrary diagram to a combination of a finite number of basis integrals. Here
I discuss various ways to calculate non-trivial bases integrals, either exactly
or as expansions in epsilon. Some integrals of these two classes are related to
each other by inversion, which provides a useful cross-check.
