1. T-elements: State of the art and future trends
2. Survey of trefftz-type element formulations
3. Shape optimization based on hybrid-Trefftz displacement finite element analysis. Int. Rept., IST, Technical University of Lisbon, 1996.
4. (eds), Trefftz method: 70 years, special issue, Advances in Engineering Software 1995; 24.
5. (eds), Trefftz method: recent developments and perspectives, special issue, CAMES 1997; 4(3/4).