@article{1102992295,
author = {Freeman, R. S.},
title = {Closed operators and their adjoints associated with elliptic differential operators.},
journal = {Pacific J. Math.},
volume = {23},
number = {3},
year = {1967},
pages = { 71-97},
language = {en},
url = {http://dml.mathdoc.fr/item/1102992295}
}
Freeman, R. S. Closed operators and their adjoints associated with elliptic differential operators.. Pacific J. Math., Tome 23 (1967) no. 3, pp. 71-97. http://gdmltest.u-ga.fr/item/1102992295/