1. Gel'fand, I.M.: Proc. Int. Congr. Math., Stockholm, p. 74 (1962)
2. Mack, G.: Renormalization and invariance in quantum field theory. New York: Plenum Press (to appear)
3. Rühl, W.: Commun. math. Phys.30, 287 (1973);34, 149 (1973)
4. Ferrara, S., Gatto, R., Grillo, A.: Springer tracts in modern physics, Vol. 67. Berlin-Heidelberg-New York: Springer 1973; Ann. Phys. (N.Y.)76, 161 (1973)
5. Todorov, I.T.: Conformal invariant quantum field theory with anomalous dimensions, Cargése Lectures (1973)