Original Data For 1930 Were Computed By NBER From Percentage Changes From The Corresponding Month In 1929 Which Were Supplied In A Mimeograph Sheet By The Federal Reserve Board. Source: Federal Reserve Board, Bulletin Of December 1927, Pp. 826-827, And Following Issues
This NBER data series m06020 appears on the NBER website in Chapter 6 at http://www.nber.org/databases/macrohistory/contents/chapter06.html.
NBER Indicator: m06020
Release: NBER Macrohistory Database
National Bureau of Economic Research, Index of Wholesale Trade, Hardware Sales for United States [M06020USM331NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M06020USM331NNBR/, September 4, 2015.