2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/111259A perturbative approach to quantum field theory involves the computation of loop integrals, as soon as one goes beyond the leading term in the perturbative expansion. First I review standard techniques for the computation of loop integrals. In a second part I discuss more advanced algorithms. For these algorithms algebraic methods play an important role. A special section is devoted to multiple polylogarithms. I tried to make these notes self-contained and accessible both to physicists and mathematicians.49 pages, to appear in the proceedings of the workshop "Renormalization and Universality in Mathematical Physics", held at the Fields Institute, Toronto, October 2005High Energy Physics - Phenomenologytext