Dennis Ritchie in co-writing the C Language, and the book that accompanied it, has probably provided me, and my family, with more money than anything else I've ever read, studied, or undertaken. It has been more valuable to me, in wages earned, than a college degree.
I still have the first edition of this book; I doubt it is even 100 pages.
I remember reading it after having programmed in Fortran, Basic, machine code, and Algo. I got goose bumps when I got to the part about functions, pointers and stacks. I could just imagine all of the re-usuable software that was going to be invented and made available.
While known for the C programming language, if not for them, we would not have UNIX today, nor Linux, nor Android, nor......
Sometime, for a gift, I'm hoping my family can get together and get my book framed, like people do for college degrees. It was my graduate program.