@article{700397,
     title = {The Helmholtz decomposition in arbitrary unbounded domains - a theory beyond},
     booktitle = {Proceedings of Equadiff 11},
     series = {GDML\_Books},
     publisher = {Comenius University Press},
     address = {Bratislava},
     year = {2007},
     pages = {77-85},
     url = {http://dml.mathdoc.fr/item/700397}
}

Farwig, Reinhard; Kozono, Hideo; Sohr, Hermann. The Helmholtz decomposition in arbitrary unbounded domains - a theory beyond, dans Proceedings of Equadiff 11, GDML_Books,  (2007), pp. 77-85. http://gdmltest.u-ga.fr/item/700397/