1. Lanczos C.,The Variational Principles of Mechanics(Dover, New York, USA, 1986)
2. Goldstein H., Poole C.P., Safko J.F.,Classical Mechanics, (Pearson Education, London, UK, 2001)
3. Finsler geometrical path integral
4. Ootsuka T., arXiv:1206.6040v1 (2012)