[1] R. A. Adams:
Compact imbeddings of weighted Sobolev space on unbounded domains. J. Differential Equations 9 (1971), 325-334.
MR 0275145
[3] A. Kufner B. Opic:
How to define reasonably weighted Sobolev spaces. Comment. Math. Univ. Carolinae, 25 (3) (1984), 537-554.
MR 0775568