1. New geological and biostratigraphical data on the Silurian in SE-Sardinia. Close affinity with Thuringia;Barca;Bolletino della Societá Geologica Italiana,1990
2. Pelecypod-graptolite asociation in the Old World Silurian;Berry;Geol. Soc. Am. Bull.,1967
3. Silurian and Devonian graptolites of Central Nevada;Berry;University of California Publications in Geological Sciences,1975
4. Über ein neues interessantes Fossil (Hallotheca n.g.) und eine neue Cyrtograptenart (Cyrt. hemmanni n. sp.) aus dem thüringischen Silur;Bouček;Beitrage zur geologie von Thüringen,1934
5. Evolution and Extinction Rate Controls;Boucot,1975