A. Lasenby, C. Doran, and S. Gull. (2004)cite arxiv:gr-qc/0405033Comment: 112 pages, 6 figures. Published in Phil. Trans. R. Soc. Lond. A 356, 487-582 (1998). Revised version with some corrections and improvements.
A. Lasenby, C. Doran, and S. Gull. Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, 356 (1737):
487--582(1998)