1. G. Audit., Phys. Rev. C15, 1415 (1977).
2. J. Bergstrom., Nucl. Phys. A251, 401 (1975).
3. J.B. Cammarata and T.W. Donnelly, Nucl. Phys. A267, 365 (1976).
4. J.C. Alder., Meson-Nuclear Physics, 1976 (Carnegie-Mellon Conference), AIP Conf. Proc. No. 23, p. 626 - 7.
5. J.C. Alder., Contribution C14, 7th International Conference on High Energy Physics and Nuclear Structure, Zurich, 1977.