Trichophycus Fossil
International Subcommission on Cambrian Stratigraphy
www.palaeontology.geo.uu.se/ISCS/ISCS_GSSPs.html
International Commission on Stratigraphy
http://www.palaeontology.geo.uu.se/ISCS/ISCS_GSSPs.html
Trichophycus Fossil
Jeolojik Devirler
www.biltek.tubitak.gov.tr/bilgipaket
