1. H. Frizsch andM. Gell-Mann: Talk presented atInternational Conference on Duality and Symmetry, Tel-Aviv, Israel, April 5–7, 1971.
2. J. M. Cornwall andR. Jackiw: UCLA preprint (1971).
3. D. J. Gross andS. B. Treiman: Princeton University preprint (1971).
4. G. Domokos: Johns Hopkins University preprint NYO-4076-18 (1971).
5. C. H. Llewellyn Smith: to be published.