1. New Peri-Gondwanan occurrences of Early Tremadoc graptolites from South America and southwestern Europe;Aceñolaza;Graptolite News,1995
2. Estructuras nemales de Araneograptus murrayi (J. Hall) (graptolito del Ordovícico Inferior) y actualización del registro perigondwánico de la especie;Aceñolaza,1996
3. Faunas de conodontes y graptolitos del Paleozoico inferior en la Cordillera Oriental argentina;Albanesi,2008
4. The Ordovician graptolites Azygograptus and Jishougraptus in Scandinavia and Britain;Beckly;Palaeontology,1991
5. The new chronostratigraphic classification of the Ordovician System and its relations to major regional series and stages and to δ13C chemostratigraphy;Bergström;Lethaia,2009