Correlation of upper Llandovery betonites in the Baltic regionKiipli, Tarmo; Kallaste, Toivo; Kiipli, Enli; Mikli, Valdek; Kägu, MarisThe Fifth Baltic Stratigraphical Conference "Basin Stratigraphy - Modern Methods and Problems" : September 22-27, 2002, Vilnius, Lithuania : extended abstracts2002 / p. 80-83