@article{urn:eudml:doc:43823,
title = {Reflection principles for the iterated Helmholtz equation.},
journal = {Collectanea Mathematica},
volume = {26},
year = {1975},
pages = {253-266},
zbl = {0333.35023},
language = {en},
url = {http://dml.mathdoc.fr/item/urn:eudml:doc:43823}
}
Díaz, J. B. Reflection principles for the iterated Helmholtz equation.. Collectanea Mathematica, Tome 26 (1975) pp. 253-266. http://gdmltest.u-ga.fr/item/urn:eudml:doc:43823/