Differential Forms and the Geometry of General Relativity - Tevian Dray - Google Books

https://books.google.de/books?id=eozaBAAAQBAJ&pg=PA39#v=onepage

Differential Forms and the Geometry of General Relativity provides readers with a coherent path to understanding relativity. Requiring little more than calculus and some linear algebra, it helps readers learn just enough differential geometry to grasp the…