For many, the "barrier to entry" for tensor analysis is the notation (subscripts and superscripts). Wrede introduces the Einstein summation convention and covariant/contravariant indices in a way that builds intuition rather than confusion.
: Fundamental notions of n-space, Riemannian geometry, and the curvature tensor. Applications Introduction To Vector And Tensor Analysis Wrede Pdf
It provides a masterclass in using Einstein summation convention, covariant, and contravariant indices. For many, the "barrier to entry" for tensor
is a foundational mathematical text originally published in 1963 by John Wiley & Sons and later reprinted as a popular Dover Books on Mathematics Google Books Introduction To Vector And Tensor Analysis Wrede Pdf