From the reviews of the second edition:
This new edition is very much expanded, up to the point that it can be considered an almost entirely new book. ... I was a PhD student in the early 90's, and I have been studying and using it continuously since then. It has accompanied me and many others as a valuable source for results and as a standard reference on the subject. I am sure that this new edition will be serving in the same role as well. (Pietro Celada, Mathematical Reviews, Issue 2008 m)
The present monograph has been ... a 'revised and augmented edition to Direct Methods in the Calculus of Variations'. ... the author maintains a fresh and lucid style, resulting in a concise, very well readable presentation. Surely this book will define a long-lasting standard in its area. ... The exhaustive bibliography comprises 621 references and covers the relevant publications in the area ... . (Marcus Wagner, Zentralblatt MATH, Vol. 1140, 2008)
This is a substantially extended new edition of the author's introduction to direct methods in the calculus of variations. ... The author has taken great care to include all the main developments in the area since the first edition (the list of references comprises 621 items). The book is carefully written and provides a very readable introduction to the field. (M. Kunzinger, Monatshefte fur Mathematik, Vol. 160 (4), July, 2010)