1. The Piru Gorge flora of Southern California;Axelrod;Carnegie Inst. Washington Publ.,1950
2. Oligocene Plants from the Upper Ruby River Basin, Southwestern Montana;Becker;Geol. Soc. Am. Mem.,1961
3. Late-Quaternary pollen and plant macrofossil stratigraphy at Lochan an Druim, northwest Scotland;Birks,1984
4. The palynostratigraphy and age of the Newark Supergroup;Cornet,1977
5. Palynology and age of clays exposed in Lawrence Clay Pit, Henry County, Tennessee;Elsik;Paleontographica, Abt. B, Bd.,1974