First 6 chapters include theory of fields and sufficient conditions for weak and strong extrema. Chapter 7 considers application of variation methods to systems with infinite degrees of freedom, and Chapter 8 deals with direct methods in the calculus of variations. Problems follow each chapter and the 2 appendices.
Here's a sample of other books in this Dover category
The Variational Theory of Geodesics by M. M. Postnikov Compact, self-contained text by noted theorist presents the most fundamental aspects of modern differential geometry as well as the basic tools required for the study of Morse theory. 1967 edition.
Calculus of Variations by Lev D. Elsgolc This text offers an introduction to the fundamentals and standard methods of the calculus of variations, covering fixed and movable boundaries, plus solutions of variational problems. 1961 edition.
Gauge Theory and Variational Principles by David Bleecker Covers principal fiber bundles and connections; curvature; particle fields, Lagrangians, and gauge invariance; inhomogeneous field equations; free Dirac electron fields; calculus on frame bundle; and unification of gauge fields and gravitation. 1981 edition
Calculus: An Intuitive and Physical Approach (Second Edition) by Morris Kline Application-oriented introduction relates the subject as closely as possible to science with explorations of the derivative; differentiation and integration of the powers of x; theorems on differentiation, antidifferentiation; the chain rule; trigonometric functions; more. Examples. 1967 edition.
