Appendix C: Indexes and Values for Minor Classes, 1879–1923, and Description of Composition and Sources of Data

Robert E. Lipsey, Price and Quantity Trends in the Foreign Trade of the United States (Princeton University Press, 1963), https://www.nber.org/books-and-chapters/price-and-quantity-trends-foreign-trade-united-states/appendix-c-indexes-and-values-minor-classes-1879-1923-and-description-composition-and-sources-data.