File(s): https://fraser.stlouisfed.org/scribd/?toc_id=499467&filepath=/docs/publications/frbslreview/rev_stls_197311.pdf&start_page=6#scribd-open

File(s): File format is application/pdf https://files.stlouisfed.org/files/htdocs/publications/review/73/11/Measurement_Nov1973.pdf