@article{02171817,
title = {The second-order Klein-Gordon field equation.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {2004},
year = {2004},
pages = {3775-3781},
doi = {10.1155/S0161171204406565},
zbl = {1084.81027},
language = {en},
url = {http://dml.mathdoc.fr/item/02171817}
}
Gomes, D.; Capelas de Oliveira, E. The second-order Klein-Gordon field equation.. International Journal of Mathematics and Mathematical Sciences, Tome 2004 (2004) pp. 3775-3781. doi : 10.1155/S0161171204406565. http://gdmltest.u-ga.fr/item/02171817/