1. W. R. Frazer:Proceedings of the XIV International Conference on High Energy Physics, Vienna, 1968 (edited byJ. Prentki andJ. Steinberger).
2. R. Dolen, D. Horn andC. Schmid:Phys. Rev.,166, 1768 (1968).
3. G. Veneziano:Nuovo Cimento,57 A, 190 (1968).
4. The 5-point function was given byK. Bardakci andH. Ruegg:Phys. Lett.,28 B, 342 (1968); and byM. A. Virasoro:Phys. Rev. Lett.,22, 37 (1969).
5. The generalization to an arbitraryN-point function was given byH. M. Chan:Phys. Lett.,28 B, 425 (1969);H. M. Chan andTsou S. Tsun:Phys. Lett.,28 B, 485 (1969);C. Goebel andB. Sakita:Phys. Rev. Lett.,22, 257 (1969);K. Bardakci andH. Ruegg: Berkeley preprint (Dec. 1968).