[delta]13C record of the Upper Ordovician succession of the Borenshult-1 core (Motala, Sweden) and its intracontinental correlationLechnert, O.; Calner, M.; Joachimski, Michael M.; Buggisch, W.; Nõlvak, JaakThe Seventh Baltic Stratigraphical Conference : 17-18 May 2008, Tallinn, Estonia : abstracts & field guide2008 / p. 40

Silurian stratigraphy of Central Iran - an updateHairapetian, Vachik; Ghobadi Pour, Mansoureh; Popov, Leonid E.; Männik, Peep; Miller, C. GilesActa Geologica Polonica2017 / p. 201-233 : ill https://doi.org/10.1515/agp-2017-0014

The Pirgu Regional Stage (Upper Ordovician) in the East Baltic : lithostratigraphy, biozonation, and correlationHints, Linda; Oraspõld, Asta; Nõlvak, JaakProceedings of the Estonian Academy of Sciences. Geology2005 / 4, p. 225-259 : ill