  We propose Mstab, a novel Krylov subspace recycling method for the iterative
solution of sequences of linear systems with fixed system matrix and changing
right-hand sides. This new method is a straight and simple generalization of
IDRstab. IDRstab in turn is a very efficient method and generalization of
BiCGStab.
  The theory of Mstab is based on a generalization of the IDR theorem and
Sonneveld spaces.
  Numerical experiments indicate that Mstab can solve sequences of linear
systems faster than its corresponding IDRstab variant. Instead, when solving a
single system both methods are identical.
