1. K. Prelec, in Proceedings of the Third European Workshop on Production Applications of Light Negative Ions, Amersfoort, The Netherlands, 17–19 Feb. 1988.
2. K. Prelec, in Proceedings of the European Particle Accelerator Conference, Rome, Italy, 6–11 June 1988.
3. K. Prelec, J. G. Alessi, A. Kponou, and A. McNerney, in Proceedings of the Second European Workshop on Production and Applications of Light Negative Ions, Palaiseau, France, 5–7 March 1986.
4. K. Prelec, in Proceedings of the 1989 Particle Accelerator Conference, Chicago, March 1989.
5. P. Allison, inProceedings of the Fourth International Symposium on Production and Neutralization of Negative Ions and Beams, Brookhaven, 1986, AIP Conf. Proc. No. 158 (American Institute of Physics, New York, 1987), p. 465.