Bondi, H.; Van Der Burg, M. G. J.; Metzner, A. W. K. (1962). «Gravitational Waves in General Relativity. VII. Waves from Axi-Symmetric Isolated Systems». Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences269 (1336): 21. doi:10.1098/rspa.1962.0161. Bibcode: 1962RSPSA.269...21B.
Bondi, H.; Van Der Burg, M. G. J.; Metzner, A. W. K. (1962). «Gravitational Waves in General Relativity. VII. Waves from Axi-Symmetric Isolated Systems». Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences269 (1336): 21. doi:10.1098/rspa.1962.0161. Bibcode: 1962RSPSA.269...21B.
Bondi, H.; Van Der Burg, M. G. J.; Metzner, A. W. K. (1962). «Gravitational Waves in General Relativity. VII. Waves from Axi-Symmetric Isolated Systems». Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences269 (1336): 21. doi:10.1098/rspa.1962.0161. Bibcode: 1962RSPSA.269...21B.
Bondi, H.; Van Der Burg, M. G. J.; Metzner, A. W. K. (1962). «Gravitational Waves in General Relativity. VII. Waves from Axi-Symmetric Isolated Systems». Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences269 (1336): 21. doi:10.1098/rspa.1962.0161. Bibcode: 1962RSPSA.269...21B.