Leffingwell, R. C. 1878-1960 Leffingwell, Russell Cornell Leffingwell, R.C. (Russell Cornell) 214 2024-08-07 16:07:57 naf author https://fraser.stlouisfed.org/author/r-c-leffingwell-1878-1960 https://fraser.stlouisfed.org/api/author/214