- Operator theory (7)
- Operator theory--Congresses (6)
- Interpolation (3)
- Matrices (3)
- Linear operators (2)
- Boundary value problems--Congresses (1)
- Control theory (1)
- Eigenvalues (1)
- Fourier transformations (1)
- Functions of complex variables (1)
- Functions of complex variables--Congresses (1)
- Hellinger, Ernst, b. 1883 (1)
- Integral operators (1)
- Interpolation spaces (1)
- Linear systems (1)
- Matrices--Congresses (1)
- Nonselfadjoint operators--Congresses (1)
- Singular integrals--Congresses (1)
- System analysis (1)
- Toeplitz operators (1)
- Wiener-Hopf equations (1)