A chief requirement in the study of relativity is absolute differential calculus, which Einstein used to mathematically develop his ideas. This classic was written by a founder in the field, offering a clear, detailed exposition. It examines introductory theories, the fundamental quadratic form and the absolute differential calculus, and physical applications. 1926 edition.
Tensor Calculus by J. L. Synge, A. Schild Fundamental introduction of absolute differential calculus and for those interested in applications of tensor calculus to mathematical physics and engineering. Topics include spaces and tensors; basic operations in Riemannian space, curvature of space, more.
Tensors, Differential Forms, and Variational Principles by David Lovelock, Hanno Rund Incisive, self-contained account of tensor analysis and the calculus of exterior differential forms, interaction between the concept of invariance and the calculus of variations. Emphasis is on analytical techniques. Includes problems.