• Middle and Upper Ordovician carbon isotope stratigraphy in Baltoscandia: towards a regional chemostratigraphic standardAinsaar, Leho; Kaljo, Dimitri; Martma, Tõnu; Meidla, TõnuThe Seventh Baltic Stratigraphical Conference : 17-18 May 2008, Tallinn, Estonia : abstracts & field guide2008 / p. 9