1. Proc. Int. Conf. on the Physics of Electronic and Atomic Collissions;Delaunay,1985
2. Proc. ECOSS 8;Zehner,1986
3. S.T. de Zwart, T. Fried, D.O. Boerma, R. Hoekstra, A.G. Drentje and A.L. Boers, to be published in Surf. Sci. Lett.
4. The ECR ion source and associated equipment at the KVI