Searching for the Hidden Economy : Economists Believe as Much as 10 Percent of the U.S. Economy Is "Underground." Is That Such a Bad Thing?
Campbell, Doug. "Searching for the Hidden Economy : Economists Believe as Much as 10 Percent of the U.S. Economy Is "Underground." Is That Such a Bad Thing?," in Federal Reserve Bank of Richmond. "Spring 2005, Volume 9, Number 2," Econ Focus (Federal Reserve Bank of Richmond) (Spring 2005) : 18-21. https://fraser.stlouisfed.org/title/3941/item/476929/toc/503893 , accessed on March 24, 2023.