  We comment on the algorithm to compute periods using hyperlogarithms, applied
to massless Feynman integrals in the parametric representation. Explicitly, we
give results for all three-loop propagators with arbitrary insertions including
order $\varepsilon^4$ and show examples at four and more loops.
  Further we prove that all coefficients of the $\varepsilon$-expansion of
these integrals are rational linear combinations of multiple zeta values and in
some cases possibly also alternating Euler sums.
