The under-the-radar books early retirees and savvy investors are reading to get ahead

Gabri Solera/Europa Press via Getty Images Business Insider rounded up the books that investors say have shaped their thinking about money. One financially independent NYC-based couple drew inspiration from "Die With Zero." Another savvy investor thinks "Work Optional" is an "incredibly underrated" money book. If you've read a business or finance book roundup, chances are "Rich Dad Poor Dad" made the list. So many investors have cited Robert Kiyosaki's classic that this Business Insider rep...