1. H.B. Nielsen, A physical interpretation of the integrand of the n-point Veneziano model, Nordita preprint (1969).
2. H.B. Nielsen, An almost physical interpretation of the integrand of the n-point Veneziano model, preprint at Niels Bohr Institute (1969).
3. H.B. Nielsen, An almost physical interpretation of the integrand of the n-point Veneziano model, presented at the 15th International Conference on High Energy Physics, August 26-September 4, Kiev, Russia (1970).
4. Y. Nambu, Quark Model and the factorization of the Veneziano amplitude, in Proceedings of the International Conference on Symmetries and Quark Models, June 18-20, 1969, R. Chand ed., Gordon and Breach, New York U.S.A. (1969), reprinted in Broken Symmetry Selected Papers, Y. Nambu et al. eds., World Scientific, Singapore (1995).
5. Y. Nambu, Duality and hadrondynamics, Lecture notes prepared for Copenhagen summer school (1970), reprinted in Broken Symmetry Selected Papers, Y. Nambu et al. eds., World Scientific, Singapore (1995).