Raw Data For 1930 Were Computed By Multiplying Adjusted Figures By The Federal Reserve Board Seasonal Index. The Derived Raw Data Were Then Seasonally Adjusted By The NBER Index. Source: Federal Reserve Board, Bulletin Of December 1927, Pp. 826-827, And Following Issues
This NBER data series m06018 appears on the NBER website in Chapter 6 at http://www.nber.org/databases/macrohistory/contents/chapter06.html.
NBER Indicator: m06018
Release: NBER Macrohistory Database
National Bureau of Economic Research, Wholesale Trade Index, Drugs for United States [M06018USM331NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M06018USM331NNBR/, November 28, 2015.