Efficient use of the Generalized Eigenvalue Problem
  We analyze the systematic errors made when using the generalized eigenvalue problem to extract energies and matrix elements in lattice gauge theory. Effective theories such as HQET are also discussed. Numerical results are shown for the extraction of ground-state and excited B-meson masses and the ground-state decay constant in the static approximation. 
B. Blossier, G. von Hippel, T. Mendes, R. Sommer and M. Della Morte