PARTIAL DIFFERENTIAL EQUATIONS AND HILBERT Space by Karl E. Gustafson 1987 HC

METHODS OF HILBERT SPACES by KRZYSZTOF MAURIN (2nd Rev. Ed.)

A HILBERT SPACE PROBLEM BOOK by Paul R. Halmos

Hilbert Space Methods in Partial Differential Equations (Dover Books on Math...

Dover Books on Mathematics Ser.: Hilbert Space Methods in Partial...

Mathematical Methods in Physics: Distributions, Hilbert Space Operators, and...

Introduction to Hilbert Space, 1957 2nd Edition, Paul Halmos

Dover Books on Physics Ser.: Quantum Mechanics in Hilbert Space by Eduard...