# References for Planetary motion

- Isaac Newton:
*The Mathematical Principles of Natural Philosophy*, London 1687.

- Nicolaus Copernicus: On the
*Revolutions of the Heavenly Spheres*, Nürnberg 1543.

- The laws appeared in Johannes Kepler (1571-1630):
*New Astronomy*, Heidelberg 1609. They were validated in his later work: *Epitome of Copernican Astronomy*, Book V, Frankfurt 1621.

- A E L Davis: 'Some plane geometry from a cone ... '
*Mathematical Gazette*, forthcoming, July 2007.

- I. Bernard Cohen:
*The Birth of a New Physics*, Norton 1985 (up-dated), p.166.

- Johannes Kepler:
*The Harmony of the World*, Linz 1619. Stated Book V, Ch.3, Prop.8.

- A E L Davis: 'Kepler's potential proof of his Third Law' in
*Miscellanea Kepleriana*, ed. Boockman, Di Liscia, Kothmann, Augsburg 2005.