Matos J., da Rocha Z.. Frobenius-Padé approximants for d-orthogonal series: Theory and computational aspects. Applied Numerical Mathematics. 2004;52:89-112.Edit

Matos J., Rodrigues MJ, Vasconcelos PB. New implementation of the Tau method for PDEs. Journal of Computational and Applied Mathematics. 2004;164(1):555-567.Edit