@article{03685720,
title = {Projection operator techniques in Lagrangian mechanics: Symmetrically coupled oscillators.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {3},
year = {1980},
pages = {369-382},
doi = {10.1155/S0161171280000257},
zbl = {0439.20008},
language = {en},
url = {http://dml.mathdoc.fr/item/03685720}
}
Boyd, J.N.; Raychowdhury, P.N. Projection operator techniques in Lagrangian mechanics: Symmetrically coupled oscillators.. International Journal of Mathematics and Mathematical Sciences, Tome 3 (1980) pp. 369-382. doi : 10.1155/S0161171280000257. http://gdmltest.u-ga.fr/item/03685720/