@article{05054214,
title = {Relationship between Laplacian operator and D'Alembertian operator.},
journal = {Divulgaciones Matem\'aticas},
volume = {12},
year = {2004},
pages = {35-52},
zbl = {1098.53018},
language = {en},
url = {http://dml.mathdoc.fr/item/05054214}
}
Birman, Graciela S.; Desideri, Garciela M. Relationship between Laplacian operator and D'Alembertian operator.. Divulgaciones Matemáticas, Tome 12 (2004) pp. 35-52. http://gdmltest.u-ga.fr/item/05054214/