What book to buy? Your recommendations please!

[Billy Zhao]

My work is kind enough to give allowance to buy personal improvement items up to $500 during the work from home time. Instead of buying a standing desk, I decided to use the money to buy some books. 

Can you recommend the most useful books for real estate investors from beginner to advanced? I assume some books are more for introduction and inspiration (Rich Dad Poor Dad, etc.) and some are very useful as a reference and tool (Gallinelli's Cashflow and key financial measures book). 

Thank you!

[Cody Barna]

@Billy Zhao $500 should get you plenty of books, I recommend The Millionaire Real Estate Investor by Gary Keller and Never Split the Difference by Chris Voss. Both books are extremely informative and help with various areas of business and everyday life. (ebay typically has great prices on books)