HARMONIC AND SPECTRAL ANALYSIS, Szekelyhidi, Laszlo, Very Good Book

Universitext: Introduction to the Theory of Lie Groups by Roger Godement (2017,

Analysis IV - 9783319169064

Coldwell - Theory and Operation of Spectral Analysis Using ROBFIT - - X555z

Roger Godement - Analysis III Analytic and Differential Functions M - X555z

Kantorovitz - Spectral Theory of Banach Space Operators Ck-Classifica - X555z

Dol - Symplectic Difference Systems Oscillation and Spectral Theory - X555z