9 Big Idea Business Books You Need to Read Now

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5. "Lincoln the Unknown" by Dale Carnegie.

Everyone's heard of Carnegie's classic, "How to Win Friends and Influence People." Few have heard of this out-of-print (but still available on Amazon) rarity, which he wrote four years earlier. In an era where Lincoln's people skills have received their fair share of appreciation, this book, which Carnegie spend three years working on, provides even deeper insights about one of our nation's greatest leaders.