Counting master integrals: integration-by-parts procedure with effective   mass
  We show that the new relation between master integrals recently obtained in Ref. [1] can be reproduced using the integration-by-parts technique implemented with an effective mass. In fact, this relation is recovered as a special case of a whole family of new relations between master integrals. 
Bernd A. Kniehl, Anatoly V. Kotikov
hep-ph hep-th