I notice you’re looking for a PDF of The Snowball: Warren Buffett and the Business of Life by Alice Schroeder. While I can’t provide or link to the PDF (as it’s a copyrighted book), I can tell you a bit about the story and themes of the biography.
The book traces Buffett’s life from his childhood in Omaha, Nebraska—where he was a mathematical prodigy obsessed with numbers and making money—through his studies under Benjamin Graham at Columbia, his partnership years, and his transformation of Berkshire Hathaway into a massive conglomerate.
The Snowball is the definitive biography of Warren Buffett, authorized by Buffett himself. The title comes from Buffett’s own metaphor for how wealth (and life) works: “Life is like a snowball. The important thing is finding wet snow and a really long hill.”