1. L. M. Slad, Theor. Math. Phys., 129, 1369 (2001).
2. L. M. Slad, Theor. Math. Phys., 133, 1363 (2002).
3. I. M. Gel?fand and A. M. Yaglom, Zh. Eksp. Teor. Fiz., 18, 703 (1948).
4. I. M. Gel?fand, R. A. Minlos, and Z. Ya. Shapiro, Representations of the Rotation and the Lorentz Groups and Their Applications[in Russian], Fizmatgiz, Moscow (1958);
5. English transl., Pergamon, Oxford (1963).