1. Sur la théorie de la variation des constantes arbitraires;Liouville;Journ. de Math. Pure et Appl.,1838
2. Classical Mechanics;Goldstein,1980
3. Mathematical Methods of Classical Mechanics;Arnold,1984
4. Light Transmission Optics;Marcuse,1972
5. Compression of a bundle of light rays;Marcuse;Appl. Opt.,1971