@article{03910910,
title = {Some isometrical identities in the wave equation.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {7},
year = {1984},
pages = {117-130},
doi = {10.1155/S0161171284000132},
zbl = {0571.35064},
language = {en},
url = {http://dml.mathdoc.fr/item/03910910}
}
Saitoh, Saburou. Some isometrical identities in the wave equation.. International Journal of Mathematics and Mathematical Sciences, Tome 7 (1984) pp. 117-130. doi : 10.1155/S0161171284000132. http://gdmltest.u-ga.fr/item/03910910/