Appendix E, Differences Between the National Bureau's Estimates of Consumer Instalment Credit and the Russell Sage Foundation's Estimates of All Consumer Credit

Duncan McC. Holthausen, Malcolm L. Merriam, and Rolf Nugent, The Volume of Consumer Instalment Credit, 1929-38 (NBER, 1940), https://www.nber.org/books-and-chapters/volume-consumer-instalment-credit-1929-38/appendix-e-differences-between-national-bureaus-estimates-consumer-instalment-credit-and-russell.