@article{GDZPPN002305909,
title = {Self-Adjointness of Powers of Elliptic Operators on Non-Compact Manifolds.},
journal = {Mathematische Annalen},
volume = {193},
year = {1971},
pages = {257-272},
zbl = {0235.47021},
url = {http://dml.mathdoc.fr/item/GDZPPN002305909}
}
Cordes, H.O. Self-Adjointness of Powers of Elliptic Operators on Non-Compact Manifolds.. Mathematische Annalen, Tome 193 (1971) pp. 257-272. http://gdmltest.u-ga.fr/item/GDZPPN002305909/