1. Oligocene plants from the upper Ruby River Basin, southwestern Montana;Becker;Geol. Soc. Am. Mem.,1961
2. Fossil plants of the Tertiary Beaverhead basins in southwestern Montana;Becker;Palaeontographica B,1969
3. The Metzel Ranch flora of the upper Ruby River Basin, southwestern Montana;Becker;Palaeontographica B,1972
4. The lower Eocene floras of southeastern North America;Berry;US Geol. Surv. Prof. Pap.,1916
5. A History of the Fossil Fruits and Seeds of the London Clay;Bowerbank,1840