M. Sanderson, D. Hemming, und R. Betts. Philosophical Transactions of the Royal Society A: Mathematical,
Physical and Engineering Sciences, 369 (1934):
85--98(13.01.2011)
J. Murphy, B. Booth, M. Collins, G. Harris, D. Sexton, und M. Webb. Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, 365 (1857):
1993--2028(15.08.2007)