This monograph (in two volumes) deals with non scalar variational problems arising in geometry, as harmonic mappings between Riemannian manifolds and minimal graphs, and in physics, as stable equilibrium configuations in nonlinear elasticity or for liquid crystals. The presentation is selfcontained and accessible to non specialists. Topics are treated as far as possible in an elementary way, illustrating results with simple examples; in principle, chapters and even sections are readable independently of the general context, so that parts can be easily used for graduate courses. Open questions are often mentioned and the final section of each chapter discusses references to the literature and sometimes supplementary results. Finally, a detailed Table of Contents and an extensive Index are of help to consult this monograph

This book by two of the foremost researchers and writers in the field is the first part of a treatise that covers the subject in breadth and depth, paying special attention to the historical origins of the theory. Both individually and collectively these volumes have already become standard references.

In this pioneering study, a world-renowned generative syntactician explores the impact of phenomena known as 'third factors' on syntactic change. Generative syntax has in recent times incorporated third factors – factors not specific to the language faculty – into its framework, including minimal search, labelling, determinacy and economy. Van Gelderen's study applies these principles to language change, arguing that change is a cyclical process, and that third factor principles must combine with linguistic information to fully account for the cyclical development of 'optimal' language structures. Third Factor Principles also account for language variation around that-trace phenomena, CP-deletion, and the presence of expletives and Verb-second. By linking insights from recent theoretical advances in generative syntax to phenomena from language variation and change, this book provides a unique perspective, making it essential reading for academic researchers and students in syntactic theory and historical linguistics.

The volume for the 50th season, 1940/41, includes "Repertoire, 1891-1941" [62] p. and "Solists, 1891-1941" [5] p.