References
- Gilbarg , D. and Trudinger , N.S. 1977 . Elliptic Partial Differential Equations of Second Order , Springer .
- Kondratiev , V. A. 1997 . Asymptotics of solutions to linear ellliptic equations with a nonlinear boundary condition , Petrovskogo : Trudy seminara im .
- Kondratiev , V.A. and Eidelman , S.D. 1976 . Positive solutions of linear partial differential equations . Trudy Mosc. Mat. Ob-va , 31 : 81 – 148 .