1. J. D. Walecka:Nuovo Cimento,16, 342 (1960).
2. J. Dabrowski andH. S. Köhler:Phys. Rev.,136, B 162 (1964).
3. B. W. Downs andW. E. Ware:Phys. Rev.,133, B 133 (1964).
4. G. Ranft:Nuovo Cimento,45 B, 138 (1966).
5. A. R. Bodmer andD. M. Rote: Λ-particle binding in nuclear matter, inProceedings of the International Conference on Hypernuclear Physics (Argonne National Laboratory, May 1969), edited byA. R. Bodmer andL. G. Hyman, p. 521;Nucl. Phys.,148 A, 97 (1970).