1. Miller DG. Who was Sir George Greenhill? Precision Shooting 2004; July: 49–50, 52–5.
2. British textbook of small arms. London: HMSO; 1929. London: Holland Press (Reprint), 1961. p. 288–9.
3. Greenhill AG (M.A., Professor of Mathematics to the Advanced Class of Artillery Officers). On the Rotation Required for the Stability of an Elongated Projectile. Minutes of the proceedings of the Royal Artillery Institution, vol. [X(7)], 1879, p. 577–93. (Gives the maximum allowed twist for stability, in terms of moments of inertia, projectile and air densities, projectile length, and flow parameters for a prolate spheroid (football shape.))
4. Cundill JP (Captain, R.A.). Explanatory Notes on Prof. A.G. Greenhill's Paper ‘On the Rotation Required for the Stability of an Elongated Projectile’. Minutes of the proceedings of the Royal Artillery Institution, 1881; vol. XI(2): p. 103–112. (Provides some simpler descriptions of the theory in [3]. Includes table of maximum t (for stability) in calibers for l in calibers from 2.0 to 4.0 for materials with a cavity as well as solid bullets. Densities (g/cm3) are iron, 7.207; steel, 8.000; Martini–Henry bullet 1 part tin to 12 parts lead, 10.9. The product tl is not given).
5. Greenhill AG (M.A., Professor of Mathematics to the Advanced Class of Artillery Officers). On the rotation required for the stability of an elongated projectile (An elementary demonstration). Minutes of the proceedings of the Royal Artillery Institution, vol. XI(3?), 1881, 119–23.