Skinner, Morris F. 1906-1989 Tertiary stratigraphy and frick collection of fossil vertebrates from North-Centtral Nebraska / Morris F. Skinner, F. Walker Johnson. -- New York : [s.n.], 1984 - p. 217-368 il. -- (Bulletin of the American Museum of Natural History ; 178, 3). Subjects--Topical Terms: Estratigrafía Universal Decimal Class. No.: 551.7