Trace fossils on and above the transgressive surface: substrate consistency and phosphogenesis (Lower Ordovician, St Petersburg region, Russia)

by Ershova, Victoria B., Fedorov, Peter V., Mikuláš, Radek
Source: 1. Geologica carpathica 1. 1335-0552 1. Roč. 57, č. 5 (2005), s. 415-422