1. Borchers, H.J.: Nuovo Cim.15, 784 (1960).
2. Streater, R.F., Wightman, A.S.: PCT spin and statistics and all that. New York: W. A. Benjamin 1964.
3. Kamefuchi, S., O'Raifeartaigh, L., Salam, A.: Nucl. Phys.28, 529 (1961).
4. Taylor, J.G.: Ann. Phys. (N. Y.)68, 484 (1971).
5. Iofa, M.Z., Fainberg, V.Ya.: Soviet Physics — JETP29, 880 (1969); Kiev reports ITF 69–23, 25 (1969); TMP,1, 187 (1969).