1. Hydrodynamic and Hydromagnetic Stability;Chandrasekhar,1961
2. Note on a nonlinear eigenvalue problem;Shinbrot,1963
3. On an inequality of linear operators in a Hilbert space;Heinz;Natl. Acad. Sci. U.S.A., Publication No. 387,1955
4. The theory of self-adjoint extensions of semi-bounded Hermitian transformations and its application II;Krein;Mat. Sbornik N.S.,1947
5. Elliptic Boundary Value Problems;Agmon,1965