@article{01182329,
title = {Perturbations and nonlinear harmonic spaces. (Perturbations et espaces harmoniques non lin\'eares.)},
journal = {Annales Academiae Scientiarum Fennicae. Mathematica},
volume = {23},
year = {1998},
pages = {33-58},
zbl = {0933.31008},
language = {en},
url = {http://dml.mathdoc.fr/item/01182329}
}
Bel Hadj Rhouma, Nadra; Boukricha, Abderrahman; Mosbah, Mahel. Perturbations and nonlinear harmonic spaces. (Perturbations et espaces harmoniques non linéares.). Annales Academiae Scientiarum Fennicae. Mathematica, Tome 23 (1998) pp. 33-58. http://gdmltest.u-ga.fr/item/01182329/