This is a PDF of Mathematical Mountaintops - The Five Most Famous Problems of all time in English language & script
as authored by John Casti. The book is a wonderful science popular
intended for non-technical audience about the five most challenging problems solved in 20th century mathematics and the development of
mathematical ideas needed to solve them , their influence on mathematical thinking and
mindset of mathematicians in 20th century in-turn influencing Physics.
I have no monetary benefits from this work & it is intended for non-commercial uses only.