From the book reviews: "This is the second and final volume of a complete edition of Ernst Zermelo's collected works. ... This second volume covers his contributions to the calculus of variations and to applied mathematics and physics. ... There is much to be learned from this volume, even for those whose only interest is in Ernst Zermelo the set theorist." (J. M. Plotkin, Mathematical Reviews, July, 2014) "This is the only authoritative version of Zermelo's collected works with English translations. Therefore, it is a tour de force for anyone not only interested in Zermelo's papers, but also the historical background of many research areas of applied mathematics. I highly recommend this volume to applied mathematicians, from advanced undergraduate students up to specialists, such as those of variational problems and functional analysis." (Arturo Ortiz-Tapia, Computing Reviews, June, 2014)