United States. Bureau of Economic Analysis. "Non-SMSA Portions of Water Resources Subareas, Volume 7" in 1972 OBERS Projections : Regional Economic Activity in the United States; By Economic Area, Water Resources Region and Subarea, State, and SMSA and Non-SMSA Portions of the Areas, Historical and Projected, 1929-2020
(April 1974).
https://fraser.stlouisfed.org/title/9208/item/682146, accessed on April 6, 2025.
@FedFRASER