1. Davis, W. R., and Moss, M. K. (1963).Nuovo Cimento,27, 1492.
2. Davis, W. R., and Moss, M. K. (1965).Nuovo Cimento,38, 1531.
3. Davis, W. R., and Moss, M. K. (1965).Nuovo Cimento,38, 1558.
4. McIntosh, C. B. G. (1980). InGravitational Radiation, Collapsed Objects and Exact Solutions (Lecture Notes in Physics No. 124, Springer, Berlin).
5. Benn, I. M. (1982).Ann. Inst. Henri Poincarè,XXXVII, 67.