This very interesting book presents a systematic study of elliptic problems in smooth and Lipschitz domains. ... This modern graduate textbook is certainly an excellent starting point for any kind of further investigations. It is useful for specialists and researchers working in the fields of partial differential equations and mathematical physics. This book is also suitable as an introduction to the themes described above. (Gunter Berger, Mathematical Reviews, April, 2016) This book should be very useful for all mathematicians and mathematical physicists who want to learn the powerful techniques related to the properties of Sobolev spaces. It is also addressed to graduate students and young researchers interested in new ideas linking all the subjects involved. (Vicentiu D. Radulescu, zbMATH 1322.46002, 2015)