1. Benn, I. M., and Tucker, R. W. (1987).An Introduction to Spinors and Geometry with Applications in Physics, Bristol, England.
2. Duffin, R. J. (1938).Physical Review,54, 1114.
3. Gel'fand, I. M., Minlos, R. A., and Shapiro, Z. Ya. (1961).Representations of the Rotation and Lorentz Groups and Their Applications, Pergamon Press, Oxford, pp. 270–271, 307–309.
4. Kähler, E. (1962).Rendiconti di Matematica,21, 425.
5. Kemmer, N. (1939).Proceedings of the Royal Society of London A,173, 91.