1. A comprehensive review of this field of research was given recently by Bencze, G.: Invited talk to the European Symposium on Few Body Problems in Nuclear and Particle Physics, 1980, Sesimbra, Portugal, see also references quoted there
2. Furutani, H., Kanada, H., Kaneko, T., Nagata, S., Nishioka, H., Okabe, S., Saito, S., Sakuda, T., Seya, M.: Suppl. Prog. Theor. Phys.68, 193 (1980)
3. Chuu, D.S., Han, C.S., Lin, D.L.: Phys. Rev. C9, 2086 (1974)
4. Zahn, W.: Nucl. Phys. A269, 138 (1976)
5. Fonseca, A.C., Revai, J.: Contribution to the Clustering Aspects of Nuclear Structure and Nuclear Reactions, 1978. Winnipeg, Canada AIP Conference Proceedings