Tschudy, B. D. (1973). Palynology of the upper Campanian (Cretaceous) Judith River Formation, north-central Montana. US Geological Survey Professional Paper 770, 42 pp. plus plates.
Palynology of the upper Campanian (Cretaceous) Judith River Formation, north-central Montana. US Geological Survey Professional Paper 770, 42 pp. plus plates.