1 “... chapter is preceded by a thorough discussion of the investigated problems, along with their motivation...”

2 “... analysis, distributions, and the theory of functional spaces, and in each chapter the problems are preceded...”

3 “... in the preceding volume, functional analytic methods are used in this volume. This textbook can be chosen for a...”

4 “...; - thorough explanations preceding definitions, theorems and formal proofs; - illustrations to support...”

5 “... section, in a chronological order. Difficult to understand abstract notions are preceded by informal...”

6 “... presented in this text are preceded by detailed explanations describing the thought process one goes through...”

7 “.... The exercises are arranged on topics, many of them being preceded by supporting theory. Content starts...”

8 “... elegant Euler products and the remaining entries on continued fractions not discussed in the preceding...”

9 “... manner so that each chapter builds on the ones preceding. Researchers and students alike will also...”

10 “... discovered since the author's preceding book entitled Linking Methods in Critical Point Theory. Written in a...”

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