1. Antsygin, N.J.A., Nasedkina, V.A., 1997. Correlation levels in the Ordovician of the Urals. WOGOGOB abstracts and presentations, St. Petersburg.
2. Late Llandovery bentonites from Gotland, Sweden, as chemostratigraphic markers;Batchelor;J. Geol. Soc., London,1994
3. Metabentonite geochemistry: magmatic cycles and graptolite extinctions at Dob's Linn, southern Scotland;Batchelor;Trans. R. Soc. Edinburgh, Earth Sci.,1988
4. Use of graphic correlation for assessing event-stratigraphic significance and trans-atlantic relationships of Ordovician K-bentonites;Bergström;Proc. Acad. Sci. Estonian SSR, Geol.,1989
5. Silurian K-bentonites in the Iapetus region: a preliminary event-stratigraphic and tectonomagmatic assessment;Bergström;Geol. Fören. Stockholm Förh.,1992