1. The nature of the stratigraphical record;Ager,1973
2. The stratigraphic code and what it implies;Ager,1984
3. First North American land mammal ages of the Cenozoic era;Archibald,1987
4. The Jurassic system in Great Britain;Arkell,1933
5. Standard of the European Jurassic;Arkell;Geol. Soc. Am. Bull.,1946