Variational Methods in Lorentzian Geometry, Vol. 309 Book

I decided to read through this book to see if it was worth studying in detail. As in a few pages a day and writing out mostly everything by hand to really learn the material. What I have found was a lot of the things covered in this book are in any modern calculus book and because of the old notation used in equations and the amount of skips in the proofs, etc. I was constantly going back to my calculus book to fill in what Hardy left out. So I said to myself I might as well be reading my calculus book than Hardy's book. The techniques on integration seem dated. If you want a book with similar integral problems look at the PDF of N. Piskunov Differential and Integral Calculus. He gives examples and steps that are very easy to follow. I learned that one of the integration techniques is called Euler substitution. Google it for yourself. Sure this book my have things others do not, but you can compare 10 modern math books and they each will have something not in the other. The problems require a skill that reading the book will not give you. Many are modern day Putnam equivalent. They are part of the Mathematical Tripos and students had to spend 3 years to prepare for the test to graduate. To do well you had to hire coaches, and their only job was to prepare you for the exam. So the problems are probably not the best for self study, unless you've had training in math competitions. I have the 10th edition 1952 and I've only been reading it for a short time but the cover is becoming frail and rough in my hands. It was perfectly smooth and I only read it in my room.