1. Golfand, Yu. A., Likhtman, E.P.: JETP Letters13, 452 (1971)
2. Wess, J., Zumino, B.: Nucl. Phys. B70, 39 (1974); Phys. Lett. B49, 52 (1974)
3. Freedman, D.Z., Nieuwenhuizen, P. van, Ferrara, S.: Phys. Rev. D13, 3214 (1976); Freedman, D.Z., Nieuwenhuizen, P. van: Phys. Rev. D14, 912 (1976)
4. Deser, S., Zumino, B.: Phys. Lett. B62, 335 (1976)
5. Trautman, A.: In: Lectures on general relativity, Brandeis 1964, Summer Institute on Theoretical Physics, Vol. I. Englewood Cliffs, NJ: Prentice Hall 1965; Hawking, S.W., Ellis, G.F.R.: The large scale structure of spacetime. New York: Cambridge University Press 1973