Steelman, Aaron. "No, Thank You : How Economics May Help Slow the Onslaught of Spam E-mail," in Federal Reserve Bank of Richmond. "Spring 2004, Volume 8, Number 2," Econ Focus (Federal Reserve Bank of Richmond) (Spring 2004) : 26-28. https://fraser.stlouisfed.org/title/3941/item/476925/toc/503809 , accessed on April 23, 2024.