For Further Information See Source Source: Pittsburgh Business Review, March 28, 1935, P.18.
This NBER data series a02069 appears on the NBER website in Chapter 2 at http://www.nber.org/databases/macrohistory/contents/chapter02.html.
NBER Indicator: a02069
Release: NBER Macrohistory Database
National Bureau of Economic Research, Net Increase In Building Lots for Pittsburgh, PA [A02069US38300A482NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/A02069US38300A482NNBR/, July 7, 2015.