Spectral and Scattering Theory for Ordinary Differential Equations Vol. I: Sturm–Liouville Equations

“The book is written in a fresh and fluent style, always starting with informal explanations before proceeding to precisely formulated definitions and theorems. Proofs are well structured and detailed without being pedantic. Each chapter has notes sketching the historical development, pointing to other approaches or indicating wider aspects. Exercises are added to each paragraph and even to some of the appendices. It provides lecturers of courses on ODEs or functional analysis with new material to demonstrate to students … .” (Hubert Kalf, zbMATH 1468.34001, 2021)