1. Non-conventional formulations for the finite element method;Freitas;Computational Mechanics,1999
2. E.M.B.R. Pereira, Elementos Finitos de Tensão-Aplicação à Análise Elástica de Estruturas, Ph.D. Thesis, Instituto Superior Técnico, Technical University of Lisbon, 1993 (in Portuguese).
3. L.M.S.S. Castro, Wavelets e Séries de Walsh em Elementos Finitos, Ph.D. Thesis, Instituto Superior Técnico, Technical University of Lisbon, 1996 (in Portuguese).
4. Mixed and Hybrid Finite Element Methods, Springer Series in Computational Mathematics;Brezzi,1991
5. Application of the Mathieu series to the boundary integral method;Freitas;Computers & Structures,1991