Warren Buffett didn't become a billionaire by chance. He has made wise investing choices by playing the long game and by acquiring a vast amount of knowledge.

Buffett reportedly spends as much as six hours a day reading books. It may be a daunting prospect for most busy people, but if you're up to the task, the Oracle of Omaha advises that we "read 500 pages every day." He says that's how knowledge works -- it builds up like compound interest.

To that end, here are five books that Buffett has personally recommended over his notorious career. 

1. The Intelligent Investor

Only Buffett's words will do The Intelligent Investor justice. In the preface to the book's fourth edition, Buffett writes, "I read the first edition of this book early in 1950, when I was nineteen. I thought then that it was by far the best book about investing ever written. I still think it is." He points out that sound investment requires no more than the proper intellectual framework for decision-making. He concludes that The Intelligent Investor "precisely and clearly prescribes the proper framework."

2. One Thousand Ways to Make $1,000

Buffett credits One Thousand Ways to Make $1,000 (a rather obscure gem he found in the school library at the age of 7) with inspiring him to kickstart his career. If you can get past the dated language (the book was written in 1936), there are precious lessons embedded throughout that stand the test of time.

3. The Most Important Thing Illuminated: Uncommon Sense for the Thoughtful Investor

Buffett is no stranger to risk, but he does believe there should be a methodology behind it. To help develop that methodology, Buffett recommends Howard Marks's book, The Most Important Thing. Marks, the co-founder and chairman of Oaktree Capital Management, the largest investor in distressed securities worldwide, is renowned for his insightful assessments of market opportunity and risk.  

4.Warren Buffett's Ground Rules: Words of Wisdom From the Partnership Letters of the World's Greatest Investor 

Author and financial adviser Jeremy C. Miller does an outstanding job researching and extracting the best of Buffett's investing "ground rules" from letters Buffett wrote to his partners between 1956 and 1970. Buffett praised Warren Buffett's Ground Rules in his 2015 annual letter, stating, "If you are fascinated by investment theory and practice, you will enjoy this book."

5. Poor Charlie's Almanack: The Wit and Wisdom of Charles T. Munger

Charlie Munger, Buffett's partner and vice chairman of Berkshire Hathaway, has no shortage of his own wisdom, captured in Poor Charlie's Almanack through Munger's speeches, stories, lessons, and writings. Edited by Peter Kaufman, this monumental work is an encyclopedia of information on what it takes to be successful and to achieve greatness. Buffett has been known to recommend this book at nearly every annual shareholder's meeting.