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Ahues M, d'Almeida FD, Largillier A, Vasconcelos PB. Defect correction for spectral computations for a singular integral operator. Communications on Pure and Applied Analysis. 2006;5:241-250.Edit

Ahues M, d'Almeida FD, Largillier A, Vasconcelos PB. Spectral refinement for clustered eigenvalues of quasi-diagonal matrices. Linear Algebra and its Applications. 2006;413:394-402.Edit