REFERENCES
- Tadashi F. Tokieda, The Hopping Hoop, Amer. Math. Monthly 104 (1997) 152–154.
- Béla Bollabås, editor, Littlewood's Miscellany, Cambridge University Press, London, UK, 1986, p. 37.
- Raymond Serway, Principles of Physics, Harcourt Brace, Orlando, FL, 1994, p. 118ff.