Luttrell, Clifton B. and Gray, Charles M. "Metropolitan Area Growth : A Test of Export Base Concepts," in Federal Reserve Bank of St. Louis. "July 1970," Review (Federal Reserve Bank of St. Louis) (July 1970) : 8-23. https://fraser.stlouisfed.org/title/820/item/24272/toc/499358 , accessed on March 29, 2024.